Why did nobody ever bother to even ask Alex what he was talking about every time he asks where his brother is? Even if they don't want to remind him about the truth, it still doesn't explain why they aren't shocked that he's asking about it.
Barring Judge Holloway, I'd say it's pretty safe to assume that nobody really knows what's happened. I'm not even 100% convinced that Alex's mother knows. Adam may have told her, although even that I'm not sure about, but she sure didn't seem to have retained the information. Other than those two, who does Alex even talk to Joshua about? Wheeler? Elle? Curtis? Doc Fitch and Mayor Bartlett? Wheeler has no reason to know anything other than what Alex knows, which is that Josh is missing - he probably knows this because he's an officer and because he works with Alex's dad. Weirdly, Elle doesn't even seem to have known that Josh is missing, either - Alex telling her when she's putting up flyers seems to come as a surprise, despite how long, it's implied, that Alex has been gone. If Curtis knows anything from his position as Judge Holloway's torture BFF, and with some of his lines to Alex ("A soldier's gotta have a gun") in their first scene, it's fairly clear that he does, he doesn't seem interested in revealing it, probably because it's not his issue and he just doesn't care enough to bother, which is in character for him. As for Fitch and Bartlett, they clearly know what's happened, considering their place in the group and how they both seem to be losing it about their completely useless sacrifices, but both are so insane over the grief of what they've done and too busy coping with their own issues to really care what the hell Alex is going on about. Bartlett's so drunk I'm surprised he's managing to stand up straight, and Fitch is too busy being a total creep over Scarlet's "dollies" and kind of losing it deluding (?) himself in believing that she was living on in some way that he could still communicate with her. It's not exactly airtight by any stretch of the imagination, but there is some explanation there.
Wheeler and Elle definitely don't know what happened - as far as they're concerned, Alex was in the military and Josh just disappeared. The only people who knew the whole truth were, as said, probably the founding family heads, and they also know that Alex is delusional. Among them, Alex's mom seems pretty far gone herself, Judge Holloway seems to take some sadistic enjoyment out of watching Alex's quest (and it does make him easier for her to predict and manipulate) and Fitch was barely listening to a word Alex said (and I don't think Alex said much about Josh in their conversation anyway - he mostly kept asking about Scarlet). That leaves Mayor Bartlett, who's very drunk and emotionally broken anyway, but also seems to have some sympathy for Alex, such as when he said "you shouldn't have come back Alex, times are bad". He might not have had it in him to answer Alex's "where's my brother" with a brutally honest "he's dead and you're living a lie." That he instead answered Alex's question with a resigned "you can't save them" could be taken as a subtler way of saying the same thing.
Save mom? Way too much work!
In the scene where Alex's mom is killed by a machine, he has to make a choice about whether he should watch her die or end her suffering by killing her. So why doesn't he just use the various items and weapons he's gathered to jam the machine? He has more than enough time, and it looks like it isn't exactly in good repair anyway.
More than enough time? Really? He has about two minutes, if that. And I don't know about you, but I wouldn't have any idea what to jam where. The fact that he doesn't even try is a little weird, but I think he's shaken by what he's seeing, what he's being asked to do, and maybe - just maybe - there's a little part of him that doesn't really feel a huge urgency to save her, anyway. I'm not saying he wanted her to die - his reaction to her death makes that pretty clear - but Silent Hill is kind of all about examining those deep, buried parts of your psyche that are ugly - the things you wouldn't want anyone to know. I wouldn't exactly be surprised to find that, with the way he was treated, Alex maybe didn't feel 100% enthusiastic about saving his mother's life, sort of in the same vein as, in Silent Hill 2, James telling Mary he killed her because he couldn't stand to continue watching her suffer - but when he realizes he has to be completely truthful with himself, that he can't keep running and hiding from the truth anymore, he admits, "No, that's not true. [...] The truth is, I hated you. I wanted you out of the way. I wanted my life back...".
The timeline seems to be as follows: Alex finds his mom trapped in the rack. He tries to free her, but the machine seems to respond by tightening and so he leaves it alone while trying to figure out what to do next. His mom instead asks him to kill her, and he agonizes over that decision. Whichever choice you make, though, she then gets pulled completely apart within a few seconds. I don't think there's ever really a chance for him to clear his head, take a look at the machine and figure out how to jam it; the whole sequence, minus the interactive elements, probably only takes a minute or two, and most of that time is tied up in conversation. Plus, if the rack only had a few more turns before ripping her apart, she might've already been far too badly injured to be saved, even if he could have gotten her out.
Plans Cancelled on Account of Kid!
Why does Joshua's death stop the original plans? Even if we assume that Joshua didn't count for it what's to stop Alex's parents from drowning Alex like they were originally going to?
I think the idea is that the gods/power/whatever counted Josh as a sacrifice even though it was an accident, since he died the way their sacrifice was supposed to, by drowning. But since they hadn't chosen Josh, it failed; once that happened, the damage was done and even killing Alex wouldn't help anything. Another theory is that Adam and Lily couldn't bear to lose Alex too after Josh died, so they refused to perform their part of the ritual. I don't agree with that one so much, since if killing Alex could fix things you'd think Holloway would have made that her top priority, but she does later say "because of him, our sacrifice was in vain" as if what happened to the town was Adam's fault.
This, more or less. I think the "because of him" bit was Holloway blaming Adam for screwing up his part of the ritual by letting Josh drown instead of Alex. That Alex was chosen for the sacrifice and then Josh accidentally wound up being sacrificed instead essentially bluescreened the ritual, and cost the town its protection.
There really was nothing preventing Adam and Lillian from sacrificing Alex after Joshua's death aside from their grief - they could have gone ahead but instead chose not to. So, yes, it was Adam's fault that Shepherd's Glen is now cursed. This is reflected in the "Heart of Darkness" ("for permitting others to suffer") and "Fallen Star" ("for dereliction of duty") medals in the Medal Puzzle as well as in his letter in the Attic:
"I have failed, and they know it. They blame me. They should. I swore to protect this town, but I can't. The streets decay before our eyes. The curse we always feared has come upon us. Worse yet, The Order has returned, kidnapping and killing with impunity, brainwashing those they take in an effort to rebuild their flock. Whether they want to punish us for the exodus of our forefathers - or simply to breathe new life into the old ways, I don't know. But they've taken our people. The only thing left is to face the source of this evil, to fight it, and pray that some hope can be restored. My sole consolation is that I've finally opened my eyes to the evil in Silent Hill."
To clarify, Joshua's death didn't count as a sacrifice for the ritual because he drowned by accident (they didn't "willingly consign [their] child to the water in God's name") and he wasn't the intended sacrifice (the last name on the Shepherd Family sacrificial altar is "Alex Shepherd").
I always assumed it was a "first-born" thing. Joey and Scarlet are only children, far as we can tell. Elle's older sister is missing, since she was marked. And Alex was supposed to be the one marked, but because Joshua died—the son they had to compensate for their eventual killing of Alex—it screwed the whole deal.
Also, if you look closely, you'll see he didn't actually drown: He broke his neck on the side of the boat.
Does it actually make any sense for it to count as an 'incorrect' sacrifice? It wasn't the right kid, and it wasn't the right cause-of-death, and it wasn't ritualistic in any way, but it's just assumed to be the ritual just because some kid of Shepherd blood fell in the lake?
No, it doesn't make any sense. The idea that there was an "incorrect sacrifice" is a misconception. There was no "incorrect sacrifice" for the Shepherd family (or any sacrifice at all, as a matter of fact). What happened to the town is the result of Adam failing to sacrifice Alex, not the result of an "incorrect" sacrifice. I'll explain why. There are three conditions for the Shepherd family sacrificial ritual and they must all be fulfilled for the sacrifice to be accepted. In order for the Shepherd family sacrificial ritual to be fulfilled, Alex would had to have been drowned by Adam because: a) Alex is the intended Shepherd family sacrifice (his name is inscribed on the Shepherd family sacrificial altar), b) being drowned by someone is the Shepherd family sacrificial method (according to the Shepherd Family Contract memo in the game), and c) The sacrifice must be performed by the Shepherd's Glen Master of Arms (Adam Shepherd). Joshua's death does not count as any kind of sacrifice (correct or incorrect) because it fails all of these conditions: a) Josh was not the intended sacrifice, b) Josh fell in the water and drowned by accident, he was not physically drowned by someone else, and c) Josh was not drowned by the Shepherd's Glen Master of Arms. Judge Holloway says Adam is at fault because he didn't sacrifice Alex. So even if Holloway had tried to cut out the middleman and drowned Alex herself it would not have been accepted as legitimate because she is not the Shepherd's Glen Master of Arms. Josh's death by drowning is irony, it has nothing to do with an incorrect sacrifice. Even with Josh's death Alex could still have been drowned by Adam. What happened is that Adam chose not to, which was his failing. That's why he wrote the letter in the Shepherd house attic expressing guilt, because he still could have performed the ritual but he chose not to.
Hey Josh! Wanna go out to the lake in the middle of the night for no apparent reason?
"Hey, that sounds like a good idea, Alex!" That aside, is there actually some reason for Alex wanting to take Josh out sailing in the middle of the night (he dies at 2:06 AM)? I don't think the game offers any.
Because he wasn't supposed to. It was an act of childhood rebellion against the father Alex despised. He couldn't do it in broad daylight because he didn't actually want to get caught, but at Alex's age, "Because dad said not to" is a good enough reason to do anything.
Still, dragging his brother along seems pointless. I guess you could excuse it with "He needed a witness to his magnificently dastardly crime of breaking curfew!", but it still comes out very thin.
He brought Josh along to antagonize him. Josh was the one that wasn't allowed out on the lake. We don't know whether or not Alex was, but Josh was the one who stated they weren't supposed to go on the lake at night. Alex was trying to scare Josh and spent the entire trip antagonizing him because the entire point of the trip was to antagonize Josh. Josh has blatantly been the favorite of the family and Alex resents him for it. Breaking dad's rules was teenage rebellion; using it as an opportunity to lash out at Josh was taking out his resentment on Josh over their parents' favoritism.
It could be that I didn't see it, but I am pretty sure the flashbacks didn't hint at Alex to carrying any real resentment towards Josh. If anything his beef was with his parents. It just kinda comes out of nowhere.
There has never been a sibling in the history of the world who didn't have some beef with their siblings. It's just basic sibling rivalry.
And Joshua went along because what younger sibling doesn't want to hang out with an older sibling? Big kids do cool stuff, and it was fairly evident that Joshua rather looked up to Alex.
Also, Josh and Alex shared a bunk bed. It would be incredibly difficult for Alex to leave the room without waking Josh up, since Alex slept on the top bunk (if I recall correctly) and Josh is established to spend lots of time awake through the night with Alex's flashlight. So I'd say the easiest way for Alex to actually slip out of the house would be to take Josh along, sine he won't get tattled on that way.
So it comes down to Alex being kind of a moron then?
It comes down to Alex being a teenager with a brother who made a stupid mistake. What do you expect? A justification that absolves Alex of any and all wrongdoing? He was young and stupid, and he did something stupid and immature, with devastating consequences.
Admittedly, the consequences were far more devastating than just a normal tragic death would have been...
What's with the small family sizes?
Each of the founding families are required to sacrifice a child every generation. Except child mortality rates are very high, at least one child has to survive to adulthood to bear the next generation of sacrifice(s), and having more kids also would make it easier to stomach killing one for the survival of the town. But the founding families all have ridiculously small populations—no branch lines full of uncles and cousins, at least one family with a single-child household (that they promptly fed to the gods when the time was right—so who's going to be the sacrifice the next generation?)...
Biology strikes again
What would happen if an only child of one of the founding families (obviously one who wasn't sacrificed) grew up, got married, etc. but turned out to be sterile, and was thus physically unable to produce a new sacrifice? Would that mean the whole town was automatically royally screwed?
Probably? Evil gods are rarely portrayed as caring why they aren't getting what they were promised.
He's a bit big by now, ain't he?
If Alex was the intended sacrifice, why wait until he's clearly in his 20s and old enough/strong enough to fight back? Why not make Josh the intended sacrifice? Aside from the "a kid isn't a believable Silent Hill protagonist" reason. He's younger, weaker, and easier to kill. Plus, it would match up with the others - all the other sacrifices were Josh's age, including Nora Holloway. Even Judge Holloway seemed to see the wisdom in choosing the younger/weaker one over the grown-up Elle.