Why is Clara having such a hard time adjusting to the Doctor's regeneration, since she saw all his incarnations in "The Name of the Doctor"?
Well, she understood the concept of regeneration, but that's not to say she accepted it or was okay with it happening—we're very much in "Some new man goes sauntering away" territory here, it's just that it's the companion rather than the Doctor who can't help but think of the regeneration as a death. Especially given the stark contrast. If Eleven had regenerated into someone more like, say, Ten, she likely wouldn't have such a rough time of it, but instead he became someone who (as we can see quite quickly) is a darker, less personable Doctor. ~Celi
Oh, and Clara didn't see the Doctor's future incarnations—at that time, the Doctor was fated to die on Trenzalore.
We're talking about the woman who went through his entire time stream and saw every iteration of the doctor that has existed thus far, who personally MET nine, ten, and ten 1/2, and who has had the whole regeneration thing explained to her multiple times. She should be the LAST person shocked by this. I'd understand it as a panic-in-the-moment kind of thing until she gets used to the new doctor, but even at the end she's treating him like a completely different person who she doesn't like or trust until she gets the phone-call from 11.
She wasn't shocked by the regeneration exactly. It was because she fancied him, no matter what she might say, and was overreacting because of it (and Eleven fancied her, too, judging by his comments.) Everyone always tries and takes the high ground in these kinds of situations but, be honest, if your boyfriend/girlfriend suddenly and visibly aged 30-40 years wouldn't you be on the verge of breaking? Like it or not, love is always half physical. Or to put it another way: Imagine if Tennant regenerated into Eccleston; would Rose have still fancied him? She certainly shows no sign of it beforehand.
The above is basically it; it's not the regeneration itself that upset her, it's the fact that this man she thought she knew is now completely different. Even removing the shipping aspect, if someone you knew well and were incredibly close to suddenly became an entirely different person, it would throw you a bit no matter how much you were intellectually prepared for it. There's a difference between having knowledge of something and experiencing it directly firsthand.
Moreover, she'd only just seen Eleven aged nearly to death, and honestly believed until the very last minute that he was going to die permanently in "Time of the Doctor". For one brief conversation, she sees him young and well again, only for him to change again into a visibly-aged man. On some level, she'd already equated the Doctor becoming old with the Doctor being gone forever.
She also saw the First, the original form of the Doctor, and an old man (older than any other version other than the dying Eleventh). In fact, she has seen all of his 2000 years of life, by jumping into his timestream. Grieving over the "death" of Eleven would be fine, but her reaction is completely incoherent with what she has gone through on a very basic level, and this annoyed me greatly too. This episode would've made much more sense with Amy as a companion (even if it would remove the "boyfriend" thing), as she is the one who is familiar with only Eleven being the Doctor.
It was established in "The Day of the Doctor" that Clara only remembers "a bit" of her time in the timestream; apparently not even enough to recognize the Tenth or War Doctors on sight. In this case, it was kind of a combination of two things. 1) Even though she understood that he could regenerate, she had not experienced a regeneration first-hand. I understand that somebody could break into my house and try to rob me, but that doesn't mean that I would automatically know how to react in such a situation. When she met War and Ten, it wasn't for a terribly long time, and she made it clear then that they weren't "her" Doctor. She had no ties to them, because she effectively saw them as different people (not that one could blame her; seeing the Doctor interact with two strangers who look and act differently would give one the perception that he was interacting with two strangers who look and act differently, not literal copies of himself). She may be consciously aware of the fact that they are his past, but that's just it - they're the past. He has changed since then into the person that she has become attached to. She may not know about post-regenerative trauma and may not know why he was acting like he was. Plus, she had just been with him on Trenzalore when he told her that he once regenerated and kept the same face, and then she later saw that for herself when he regenerated on the clock tower but came out looking like... Matt Smith. So it's possible that she didn't know that those were unusual circumstances. And moreover, 2) she understood the concept of regeneration, but what threw her for a real loop was the fact that he got older. As I said, she's never experienced a regeneration first-hand. What reason would she have to think that he should go from young to old if he's being "renewed"? She saw War, yes, but she knew that he'd been in a high-stress war zone for his entire life and may have (correctly) assumed that he started out looking younger. In this case, she had just seen Eleven age tremendously over the time on Trenzalore, and she clearly didn't understand why he was starting out aged here. So there are a lot of factors present that could contribute to her mindset in this episode.
She's not having difficulty with the concept of regeneration, she's having difficulty facing the fact that "her" Doctor, Eleven, is gone and not coming back. She's not snubbing Twelve on purpose, she's upset that she's lost the Eleven she knew so well.
So the robots were the same kind as those aboard the spaceship in The Girl in the Fireplace? But in that episode the robots went crazy and started replacing the spaceship parts with human parts only because they were stranded in space, and had nothing else to use. However, the robots in this episode would have had all the inorganic raw materials they need, yet harvesting organs now seems to be their default mode? Does not compute.
You can't say the robots on the SS Madame de Pompadour had nothing but human parts to use, at least not by the time of the episode. The spatio-temporal hyperlinks gave them at least as much access to raw materials as the SS Marie Antoinette had but they still insisted on using people—or at least Reinette—for the repairs.
Okay, but if that's true, the question still remains: why were these robots programmed to use parts taken from living humans to repair things? If it had only happened with the robots of Madame de Pompadour, you could brush it off as a malfunction, but since the same happened with this other set of robots too, it seems to part of their basic programming. However, they were built and programmed by humans to help humans, so why introduce an element to their programming that can cause them to kill humans?
We don't know how widespread that bug was. All we can say is that it turned up on two sister ships (specifically noted in this episode that it is the Pompadour's sister ship) that had the same type of accident. For all we know those ships were purpose built, using the same code, and sent off together to explore strange new worlds and boldly split infinitives. Then they ran into a temporal anomaly, and the robots (for reasons of sloppy coding; good old GIGO) both defaulted to the same technique. It is entirely possible that this bug existed only on these two ships because they were paired.
For that matter, it's possible that the two ships were traveling in convoy when whatever mishap that disabled the Pompadour occurred. A control Droid on one of the ships suffered a malfunction that told it to using organic materials for repairs, and passed this instruction on to its counterpart on the other vessel. Both ships' crews were broken down for parts, but it wasn't enough to restore the vessels. The Marie attempted a time-jump to acquire the needed material for both ships, but crashed upon its arrival on Mesozoic Earth. The Pompadour's Droids, seeing that their sister ship hadn't come back, tried using time-windows instead of jumping their whole vessel into the past.
Remember that these Droids had been rebuilding themselves since the time of dinosaurs, and that incorporating parts of humans had led the Half Faced Man to acquire human qualities. Possibly, when they first arrived in the distant past, these Droids had begun incorporating Silurian tissues into their bodies, and inadvertently acquired the ancient Silurians' attitude towards hominids — namely, that they're livestock to be bred and slaughtered for meat — from their tissues. (Note that, when the Half-Faced Man says they'd repaired their ship with "you", he's addressing a group that includes Vastra.)
Why was it left ambiguous whether or not the Doctor killed the cyborg guy? The Doctor doesn't have a "no killing" code like Superman, we've seen numerous times that he's perfectly willing to kill when necessary. And in this case he was fighting for his life (as well as the lives of his friends, if he realized stopping the head cyborg would stop the others). So why is it all of a sudden ambiguous whether or not he's a killer?
Because different doctors have had very different attitudes to killing, so the question here is if this particular doctor is a killer or not.
Even if a given Doctor is okay with killing, that doesn't mean that the cyborg killing himself isn't a morally preferable situation all around. Plus, the writers probably considered the mystery valuable in itself, such that "We don't want this Doctor to be a killer" isn't the only possible reason to leave it ambiguous.
How did the dinosaur survive the trip through time time vortex unharmed?
The time vortex isn't necessarily fatal; so long as you don't try to absorb the thing, it's survivable. It's not like she was going to lose her grip in transit, what with the TARDIS stuck in her throat and all.
Probably the same way that Clara survived being exposed to the Time Vortex in the previous episode: The TARDIS reflexively extended its force field.
Into the Dalek
Why did the other Daleks let Rusty kill them without firing a single shot at it? Sure, it must be shocking to see one of your own turn against you, but are the Daleks really so inefficient they couldn't process this new information and try to shoot Rusty back?
I'm pretty sure at least one of them started to say "exterminate" or something, but was blown up. Even if they didn't, Daleks don't really seem to kill Daleks unless they're impure or something. In this case, I think they were just surprised and were struggling to understand why a Dalek (who they were sort of coming to save) would start killing them. It probably takes something drastic to make a Dalek kill another and these just couldn't react in time. I mean, when they had that planet full of insane Daleks, I'm sure it would have been better for them to be wiped out, but the 'sane' Daleks didn't want to kill them (and probably viewed them as being fantastic, if uncontrollable Daleks). They also seem to need ordered to do a lot of things and maybe found it difficult to attack without a superiorly ranked Dalek saying "stop killing humans, start killing that Dalek!".
Why is the Doctor so insistent that a 'good' Dalek cannot exist? Hasn't he met a fair few in his time? Alpha, Beta and Omega, Dalek Sec, Dalek Caan, Oswin, etc.
None of those really qualify as "good Daleks" in any proper sense. Alpha, Beta, and Omega were given the Human Factor, Sec turned himself into a human hybrid, Oswin was transitioning from human to Dalek and her ability to resist is shown breaking down at the end. They're not really good 'Daleks' in the same way a mule isn't really a horse. And Caan is legitimately insane rather than 'good'.
How did they enter the eye? Isn't it solid glass? Or at least, something solid?
Apparently not. That glowing curtain of light that they pass through upon leaving the shrunken capsule? That was the same blue dot that's in the center of a Dalek eyestalk.
The antibodies are attracted to weapons and grappling hooks, but otherwise ignore intrusions until the systems are being directly tampered with. Does being invaded my miniturized enemy soldiers seriously come up that often? It seems like they'd be worthless for any other scenario, like an insect infestation.
Probably because when Davros created the Daleks he was too arrogant to think of things like insect infestations causing his creation problems, but totally insane enough to seriously consider miniaturised soldiers.
Daleks use nanotechnology themselves to convert their enemies into drones, so their "antibodies" are probably programmed to hunt down and destroy other races' weaponized nanites. The soldiers' mechanical equipment was similar enough to such nanites to trip Rusty's defense systems. Biological threats like bacteria or insects, a Dalek would probably deal with by heating the infested compartments of its battle shell or flushing them with radiation, not by hunting them down individually with antibodies.
Robot of Sherwood
Are the robots really stupid enough to launch their ship into air without having enough gold, even though this means it won't reach escape velocity, so it will explode? And even they are that stupid, shouldn't the ship itself have some safety measures, so it won't launch until there's enough gold?
Using gold in the first place was pure improvisation on the robots' part, because they couldn't acquire the proper materials to repair their vessel in the 12th century. And considering that even managing to improvise was remarkable for a bunch of robots: yes, they really are that stupid, or at least that single-minded.
Perhaps the robots did not realize that the arrow had been stolen, and thus included it in their calculations. It would explain why they were only *just* able to reach orbit — they took off as soon as they thought they had enough gold. Once the Doctor, Robin, and Clara shot the arrow up to them, they *did* have enough gold, so it being included in their math seems likely.
When the golden arrow hits the ship, it now has enough power to reach space. So why does it explode anyway on Earth's orbit?
No amount of gold would have been sufficient, since the engines were so damaged it would have exploded whatever happened - they were leaking radiation everywhere. The robots didn't realise this, and thought they could fix it with enough gold.
Lift and explodeyness are two separate problems. The ship is going to explode because of the faulty engines and also the engines are not going to be able to deliver enough lift to gain orbit. The Doctor can fix the problem of not being able to gain orbit, but nothing can stop the explosion. It was just a question of where the explosion happened.
If Robin Hood was not a robot or a simulation, how was he able to split multiple arrows in the archery contest? As proven by The Mythbusters, the Splitting the Arrow trick is physically impossible to do as it's done in the Robin Hood legend, and in this episode. Even the Doctor had to cheat to pull it off.
Because he is the Robin Hood legend. The whole point is that the legend, in this case, is entirely true, no matter how absurd or implausible it seems. Granted, it's completely physically impossible, but then so's housing a massive spaceship and time machine within the confines of a telephone booth, so if we can stretch our willing suspension of disbelief to accept the Doctor's TARDIS despite the fact that it's completely physically impossible, then we can (or should) accept Robin's ability to split an arrow despite it also being completely physically impossible. As Robin says to the Doctor, they're both just as real as each other, and that includes the utterly impossible things they can both do.
I saw another similar show test it out, and they determined it actually was possible, just incredibly unlikely. After around thirty tries the expert archer they got managed to split one arrow with another (though not the whole way down) as Robin Hood is the best archer in England, at a time when boys were trained to be archers from around seven, I guess we can assume he is just that good.
Why is the episode titled "Robot" of Sherwood when there was more than one robot?
Parallelism to "Robin of Sherwood", no doubt. Possibly also because the pressing question throughout the episode was less about how many robots and more about whether Robin was himself one.
Why was there a gold arrow at the archery contest when the robots needed the gold?
Because the Sheriff wasn't intending to give it away, he wanted to lure Robin Hood there.
The Merry Men explicitly say they nicked it in the confusion too.
The Doctor is determined to solve the mystery of what hides in the darkness under the bed... but he already knows that the Vashta Nerada are monsters that hide in the shadows. Why would he think there's another one?
As far as we know, Vashta Nerada can't write on a chalkboard, which is what got the Doctor spooked and suspicious in the first place.
Because Vashta Nerada under a child's bed would've come out and eaten the child, leaving nobody to tell stories about the monster under the bed.
The universe is vast. Many different species could share similar traits. And the Doctor was also curious about why people speak aloud when they are alone. Really, he was just trying to determine whether or not his theoretical "perfect hiders" actually existed. He was looking for something specific.
I thought TARDI Ses weren't able to travel into Gallifrey's past?
Could the Moment's actions have altered the locks on the TARDIS?
Stable Time Loop forcing the TARDIS to break its normal rules, seeing as without it she probably won't be saved?
The Doctor mentioned that the safe-guards were turned off in the TARDIS earlier. Safeguards regarding Gallifrey's past must have been among them.
We already know that traveling through someone's personal timeline can bypass the time lock on Gallifrey, as one of Clara's duplicates got there to help One choose the right TARDIS. Twelve seems to have adapted the TARDIS to navigate by the same means, without the inconvenience of being shattered into thousands of copies of one's self.
Adding onto this, we have never seen the TARDIS (specifically the Doctor's, which is outdated (and therefore probably has inferior security features) and was stolen from a repair shop) piloted telepathically instead of mechanically before, no less with the safeguards deactivated. It already went one place that it wasn't supposed to (the end of the universe), why not another?
Who said that was necessarily on Gallifrey?
Indeed. The sky was not burnt orange in the clip from The Day of the Doctor; it could be a sister planet or moon that the Doctor lived on for a time as a child.
Or maybe Gallifrey's sky varies in color depending on the weather and time of day, same as Earth's.
If the "silent companion" meant to reference Clara, why did the Doctor talk as if everyone had them? What was the point of everyone having the dream of someone grabbing their ankle when they step out of bed? What was under that damned blanket? What was trying to get into the TARDIS? Seriously, was this episode an entire accidental What Happened to the Mouse? or was writing everything off as "maybe, maybe not" just good enough that day?
"Maybe, maybe not" was more than "just good enough that day"; it was sort of the entire point of the episode. Whether there's actually a perfect hider or not there are answers both ways. As the Doctor says, the thing under the blanket could be the thing he's looking for or it could just be another kid trying to play a trick and deciding that it was better to take the free pass to leave rather than get in trouble with the two adults that were unexpectedly there. The noises at the end of the universe could—again, as the Doctor suggests—basically "pipes banging", pressure equalising, the hall cooling, and a pressure lock on automatic after it's been released. As for the dream that everyone has, it's possible for everyone to have the same dream without having a basis in reality; in fact, this pretty much is the case in reality. Maybe there's actually a creature, maybe the Doctor is playing up the importance of something unimportant because of his experience as a kid. The entire point of the episode is "maybe, maybe not" and resolving it either way would have been rather silly.
Ultimately, the episode was about dealing with fear, not dealing with either monsters or bratty kids pretending to be monsters. Fear is something that must be coped with, irregardless of whether or not it's all in one's imagination.
The Doctor is a time traveller, and it seems the Bank of Karabraxos was the most famous bank in the universe. So wouldn't he have known it was destroyed in a solar storm in 2014?
The Doctor has always been indifferent towards money, and the Solar Storm seems to be a natural event so there is nothing he would consider exciting in its destruction. It is probably just one of those things he was vaguely aware of having happened but because it didn't impinge on any of the things that do interest him, he doesn't really know much about it. The universe is full of great institutions rising and falling, in and of itself it is not an attention grabbing thing.
For that matter, the fact that old dying Karabraxos has to tell him she was once the richest person in the universe suggests she and the bank have never been particularly famous, just known to the right (ultra-super-mega-rich) people.
He only knew about the bank because she told him about it, when she called him to ask for his help. She had to explain what exactly the job would entail.
He clearly knew about it since his plan hinged on it. But it's probably not 2014—augmented and mutated off-world humans probably aren't around at that point—and, thanks to the memory worm and the whole 'traveling through time' thing he can't know *when* it is while pulling off the heist.
There's a mention near the end of "all our facilities", which implies there are other branches of the Bank of Karabraxos all over the universe. The branch where the robbery took place was its headquarters and the location of its most secure vaults, but the corporation presumably remained in operation after the storm, albeit much-reduced in prestige and finances.
At the end, the Doctor implies that the two Tellers will be happier in the mentally-quiet peace of an uncrowded planet. But if they feed on thoughts/brains, won't that make them hungry, or even starve?
Perhaps the mindreading/mind-eating is only a defense mechanism, not a preferred basis of carnivory, and the male Teller's condition was similar to forcing an animal to survive solely by licking your floor clean.
They can probably feed from non-sapient animals.
The Doctor says that they couldn't use the TARDIS to get into the vault because there's a solar storm going on at that moment which prevents TARDIS travel. But why couldn't they use the TARDIS the day before the storm, thus bypassing all the security?
Because then the Doctor would not have gotten caught and be able to give his number to Karabraxos and been asked to do the heist in the first place (Moffat loves his ontological paradoxes).
When the Teller confronts the Doctor in the vault, why doesn't it eat his brain? Why does he bring him back for a little chat with the security chief? He didn't do that with any of his other targets.
Considering just how powerful the doctor's brain is, its entirely possible it had already taken more than it had even eaten before when it stopped, but that was still less than one per cent gone for the doctor.
He and Clara had presumably made it far enough into the bank to spark the director's curiosity as to how they'd managed it, and who'd put them up to making the attempt.
So Danny's not a PE teacher? But his first scene is him teaching PE.
That wasn't PE. That was, as their shirts said in that scene, the "Coal Hill Cadet Squad".
Kill the Moon
If the Moon's changing mass has taken out satellite communications, then just how much of the planet would Clara's message have actually reached? How many cities would have been on the wrong side of the planet to hear her, and thus have their lights on as normal? And how many major power plants are close enough to coastlines that they were taken out by flooding? Enough to cause a cascade, taking out others?
All of which leaves aside the problems of (a) how they'd see everyone at once, and (b) the fact that the entire planet en masse voted to execute the creature in under an hour. You can't get all humanity to do anything as a group in 45 minutes.
No, but maybe all the power plant managers. Which would explain why the lights go off in huge chunks the size of countries at a time.
Or maybe by that era, the electrical grids are all centrally-controlled, and equipped to be switched off en masse in response to an emergency that could damage a live grid (e.g. an EMP pulse or massive solar disturbance).
Or more alternatively, the governments of the world got in touch with each other after receiving Clara's message, deliberated a vote, and then expressed that vote using the lights on the side of the Earth that was visible from the moon. Regular citizens likely wouldn't get any say in a situation like this anyway. I don't think even Clara's intention was to judge by the majority of porch lights still on.
So, the world is no longer interested in space, and yet Mexico had a moon mining expedition? How does that make sense?
Most of the world. People just say "the world" out of convenience. It's like saying "everyone likes ice cream" even though there's people who don't.
They did say the Mexican outpost had been abandoned for years, having found no mineral wealth there.
What kind of a life form lays an egg immediately after it's been born? And how could it lay an egg that was roughly the same size as the old moon, even though the alien itself was smaller than the moon (since it fit inside it)? How is that physically possible?
Possibly the creature can convert solar energy stored up during its long gestation into matter, which would also explain how it could gain mass without eating anything. (Hey, weirder things happen all the time in the Whoniverse.) As for it laying an egg right after it's born, the real discrepancy is why it would go on living after it's reproduced? Possibly it isn't actually content to be a Single Specimen Species, and it flew off to lay another egg around Venus or Mars, rather than leaving two eggs orbiting the same planet where they might collide with one another.
But that still raises another question: in all the times the Doctor and his companions have traveled to the future (beyond 2049), how come none of them have noticed the moon is considerably smaller than it was in the 20th and early 21st century?
It's not like the Doctor and co. actively look at the moon and decides to measure it. Most of his involvements on Earth is to either have fun or stop the alien invasion/Apocalypse he doesn't have time to look at the moon and think "Hey that moon looks smaller than I remember".
Perspective does funny things to the Moon's apparent size even in Real Life: it looks considerably bigger when it's near the horizon than when it's high overhead. The size change might not be all that conspicuous, although the sudden absence of markings on its surface (since the new egg hasn't been sprinkled with debris from meteorite impacts, etc) would certainly be a giveaway. That's assuming the newly-interested-in-spaceflight humanity didn't decide to paint the darned thing to match the previous Moon, same as their descendants moved Earth's continents back into their historical positions a few billion years later.
I got the impression that the original moon had been growing in recent years, hence the surface beginning to crack. The creature inside was getting bigger. So on that, I figured that the "new" moon was the same size as the original one had been before it began to hatch.
Mummy on the Orient Express
What would happen to the soldier if the flag on the wall is destroyed? (Not necessarily during this episode.)
If the Foretold is an ancient soldier, why is he dressed in embalming wrappers?
What would have happened if a passenger marked for death killed themselves before their 66 seconds were up?
Presumably the Mummy would have detected that they no longer had energy to drain and simply moved on to another target.
Considering how it's a soldier controlled even in death by cybernetic implants, it's probably equipped to switch targets in the event that its current target gets hit by some other attack before it can reach them.
It would switch just as it does when the Doctor somehow injects himself with Maisie's mental problems.
We find out what the Foretold is after is energy, but it's never explained why it goes after the physically or mentally weak first? You'd think these people have less energy than healthy ones? In the previous experiments with the Foretold it eventually killed everyone on board, so it doesn't seem like it has trouble killing healthy folks just the same as ill ones. So there's doesn't seem to be any logic to its preferred order of killings. The Foretold's nature as a soldier doesn't explain it either, because a soldier would presumably first try to get rid of the most dangerous (and therefore most healthy) enemies, not harmless 100-year old grannies.
It's not the first time that it's been set loose on a group of scientists and one group partially figured it out before all dying or getting killed off, picking off the weakest people around the scientists would make this group of scientists panic and less likely to figure anything out about it, without the doctor they would've failed just like all the others.
Killing random people in the train is gonna make the others panic anyway, I don't see how the panic would be dependent or whether or not they are weak. Also, people actually got less panicky when they figured out the pattern to the mummy's killings. If it had killed people truly at random, that would've actually increased the panic, since anyone could be the next victim.
The fact it only killed those soon about to die, quick and painless I might add, it seems this Mummy may be more merciful than we think. In fact, maybe it had PTSD and wanted to put these people out of their misery while still gaining its desired goal of absorbing their life force.
It may have been compelled to kill, but the Mummy still had the ability to choose the victim. It was making the most merciful choice it could while still carrying out its orders. As the Doctor put it...
"Sometimes the only choices you have are bad ones but you still have to choose"
The mercy thing would explain killing the old woman, but there's no indication that the guy with bionic lungs or the woman with some psychological issues are "soon about to die"; for all we know they could live just as long as any other person on the train. And it was never said the mummy picked people about to die, the Doctor only states that it picks weak people first.
Given that the Foretold's cybernetic heart was directing its actions, presumably its programmers wanted to target the weakest enemies first, pick off the strong ones' backup.
Perhaps the cybernetic heart has concluded that the Foretold is weak, and so it's safest to choose targets who are least likely to fight back. (Of course, the Foretold is invincible against conventional weapons, but maybe the heart isn't thinking straight.)
Or possibly the Foretold was originally more of an assassin than an infantry soldier, as evidenced by its stealth capabilities. If it was originally used to slip past an enemy force's heavily-armed grunt troops and take out their lightly-armed commanders, then it may have simply designated the train's less-healthy passengers as "enemy officers" by comparison with the fit ones.
How did the Doctor figure out the 66 second thing from video of the first murder? The old woman didn't react to the Foretold until the on-screen clock shows 50 seconds.
Wasn't the 66 seconds already known in the legends that he discussed with the professor of mythology.
Yes, the mythology professor mentioned that. Also, he timed it from when the lights flickered, not from when she first reacted.
How did the idea that saying the right phrase would cause the Foretold to spare someone's life become part of the legend? When the Doctor figured it out and said "We surrender", the creature quit killing people and disintegrated, suggesting that if anyone had said the right thing to make it stop before now, the mummy would've been laid to rest long ago.
It's possible that there is another combination of words merely makes it spare the person that says them - perhaps merely saying "I surrender" or words close enough to that (which someone panicking for their life may well do by accident) would have this effect. Because no one had realised what the Foretold actually <i>was</i>, it wouldn't be clear what exactly the survivor had said right to be spared, until the Doctor was able to work out how to get it to stand down entirely.
How in the world did that kid (Rigsby? I think that was it) create such a convincing replica of a door using a single can of black paint in a matter of minutes?
It didn't have to be that realistic to fool the Boneless, as their ability to perceive things in our 3D universe was probably just as sloppy and inexperienced as their ability to replicate a 3D human body. Also, he probably had a paintbrush in his pocket left over from his community-service, that he could use to touch up the sprayed image wherever crisp edges were needed (e.g. the edges of the wheel that opens the "door"). And working fast is an important knack for any graffiti artist who's working where tagging is illegal or places you at risk of being run over, like in a train yard.
How did jumping out of that train not kill Clara and Rigsby?
It wasn't moving fast enough to kill someone if they jumped off.
Why did the Boneless' influence cause the TARDIS to shrink, when their effect on everything and everyone else was to turn them two-dimensional?
The TARDIS is dimensionally transcendental, which is why it's bigger on the inside. The Boneless were warping the dimensions so the dimension circuits were reducing the size of the outside in a similar (but opposite) way to the huge TARDIS in "The Name of the Doctor"
The TARDIS exterior requires energy to make the exterior a certain size, the Boneless were somehow draining the energy making the TARDIS smaller the more energy got drained.
To be specific, they were constantly removing the internal dimensions of the TARDIS, and she was using up her energy to put them back instantly and keep the Doctor and everything else inside her from being flattened. Having less and less energy to spare, the old girl cut back on how much went into manifesting an exterior, so that exterior kept shrinking and eventually (in siege mode) lost its chameleon-circuit camouflage.
Why did the overseer suddenly try to nick the TARDIS from Clara?
Seems like he was a designated Hate Sink since it's easy to hate what the Boneless did but there's no obvious individuals to direct hate towards. In Universe, he's a stupid Jerkass who probably figured the Doctor was giving Clara instructions and tried to leave the others for dead.
A minor one: at one points, Clara appears to be able to scramble the Doctor's reception of what she sees by waving the Sonic Screwdriver in front of the mirror she was looking into. How is that supposed to work ?
There's nanotech connected to her optic nerves, bouncing the beam off the mirror into her eyes would make it disrupt the nanotech's reception.