Personally, I see the "A"-shape as the tip of a hidden blade. The Assassin symbol IS the Blade in the Crowd
The Templars have controlled human growth for centuries. As such, they would have influenced language. In the real world, we think that an 'assassin' is merely a hired killer. Someone that is a remorseless murderer that is only in it for selfish reasons, like money. In-universe, this is probably the case, but it originally meant someone who was part of the Assassin order. The Templars managed to make 'being an assassin' equal to 'being a soulless death dealer' in the minds of the general public. If they are 'just an assassin' then it doesn't sound like some millenia-spanning conspiracy. Also, a lot of famous people are referred to as being 'assassinated' instead of 'murdered' - a covert implication that the Assassins had something to do with it?
The origin of the term "Assassin" comes from "Hashsha-shin", which is the arab word for one branch of chii-ite Islam. This is why in the first game you play as Alta´r: a muslim in Masyaf. The Templars would have probably changed its meaning when the order began to have more men in its ranks that were not muslim.
Why are there no children in the crowded cities of Jerusalem, Rome, or Istanbul? Because Altair and Ezio didn't remember them. One of the tenants of the creed is not to harm the innocent, and children are innocent. Therefore the Assassins don't perceive them as a threat and ignore them. Because of that, children don't enter their long term memory and are not seen by the Animus. The only child that was shown was Ezio's little brother, and he was seen because he was important to him.
And in Connor's game, children appear—because Connor is a caring Friend to All Living Things. Sure, the orphans are annoying to the player, but Connor who deeply cares about human injustice and suffering would have noticed and remembered them, and therefore so does the Animus.
Why is it that when you attack enemies with fists, you only attack with hooks and backhands, but not jabs? Fists are used when you want to fight enemies WITHOUT killing them. Thrusting your arm forward would accidentally bring out your hidden blade, killing them when you're not supposed to.
Don't the hidden blades, or at least Altair's, open via a ring pulling a string and activating a mechanism all caused by an open hand?
One of the most prominent features on the conventional assassin armor is that big leather sash over the midsection (it's the bit that has the assassin symbol). Assassin armor needs to be light and provide good freedom of movement, so why put the armor there of all places? Because one of the most incapacitating blows one could receive is to the solar plexus - it makes it difficult to move and draw breath with only a light hit. You may know it as getting the wind knocked out of you. Guarding against such an attack would ensure that an assassin would never get severely handicapped in a fight, and could thus always escape.
Altair seems... different when we read the Codex in AC 2, and when we see him in Revelations. In Revelations he has an accent, is calm, compassionate. It could be argued that we see him prior to his arrogance, and then just afterward, but in the original Assassins Creed we don't see a lot of his character development come through in cutscenes, certainly not as much as we see of Ezio and Connor. After thinking about it, it suddenly hit me. In AC we're playing on an Abstergo Animus. They have no reason to show us the slow development of Altair, his reactions, or the full interaction between him and his fellow assassins. In fact, they have a vested interest in not showing it. Where as the Assassins in AC 2 and beyond, they have a vested interest in showing the strong ties of family Ezio had, the better to remind Desmond of what he's been missing. This also explains the repetitiveness of the original AC, Abstergo didn't care about side quests, or supporting characters, they just wanted to blow through things as fast as possible, to do the minimal amount required to get the job done.
And related to the above; both times in the Animus are more fitting the respective ideas of the two factions; The Templar operated Animus is rigid, almost cold. Sidequests are repetitive, simple, and oriented toward achieving goals. The people you help are often faceless, you don't find out their stories, you simply handle their problems and that's it. Interaction with others is limited to what you need to do and no more.
This Troper always thought of Alta´r's accent like this: When you're in Abstergo's Animus, you can hear some Arabian that Alta´r probably did perceive, but did not hear. (Pretty much the same as when you enter a bar, you hear lots of people talking, but only listen and decipher what the ones closest to you are saying), and the English spoken by everyone is pretty much perfect. Later, at Assassin's Animus, you hear Alta´r again, this time with accents and a very different voice, because it was Ezio's memories of Alta´r's visions. He was an Italian, so for him, an accent is surely to be noticed. Either that, or Rebecca's work in Animus 2.0 and onwards to include subtitles somehow also added accents.
Lucy explained in the first game that the Animus was converting everything spoken to sound more modern, thus easier for Desmond to understand. It could just be that Altair spoke like an American because Abstergo felt it would be easier for Desmond to synch with someone who talked like he did.
By contrast the Assassin operated Animus is all about the people, sidequests range in options and some of them are just random side things you do for money or for the sake of completion. You make friends, and the friends you do make you talk to at length, you get involved in their lives and their situations.
Related to all this, in Black Flag we get another Abstergo Animus but this time it operates basically the same way Rebecca's did. Why is that? Because the "Employee" doesn't know anything about Abstergo being Templars or that Assassin's are real and is only supposed to gather material for a movie. Or that's what he is being told. If they made him go after the Observatory from the get go he would get suspicious. Why are they so focused on that and not Edward's life in particular? So we get many, many side-quests and lots of possibilities just like Desmond did with "Baby".
The announcement of "Unity" revealed a bit if foreshadowing from Assassin's Creed III where Desmond and William discuss how Templars and Assassins have never been able to work together. In particular, William mentions that the two sides "have never been able to achieve unity." One of the early trailers for this game reveals Arno, an Assassin, freeing and fighting alongside Elise, a Templar.
There are no gods, only mis-remembered stories about a powerful race of Precursors who left behind pieces of their technology. And no human being has ever been able to accomplish anything of note without that technology. Every great political, social, or spiritual leader in human history has made use of a Piece of Eden to further his or her agenda. Every great technological or cultural achievement has been a lie, an illusion, or a smokescreen, to serve some other end. Even the Apollo Program was part of a larger Templar plot. Human achievement is worthless. Human morality is meaningless. there is no good or evil; there are only human beings with hypnotic devices that make us think what they want us to think. And it's only by happy coincidence that some of the devices fell into the hands of people who are basically good.
Which in turn prompts the Assassin's Creed: "Nothing is true. Everything is permitted". I had this sudden flash of insight reading the above post.
The only thing that keeps it from being a Cosmic Horror Story is The Great Old Ones are all dead. And then the ending of AC 3 happened...
Which, along with Tyranny of King Washington, makes the Fridge Horror even worse. Humanity was NEVER free, as the Pieces of Eden were used to control all great leaders and figures, Assassins or Templars, without any of them realizing it, just by being close to them. Everything YOU have done as Altair, Ezio, Edward, Haytham, Connor and Desmond was all for Juno's plot. For all you know, most if not all your targets were heroic figures turned into Brainwashed and CrazyUnwitting Pawns of Juno. It then makes you realize the Ironic Echo in the Assassin's Creed: "Nothing Is True, Everything Is Permitted". Only it doesn't apply to philosophy or morals, but your very perception of reality! Everything you see in the game, from the moment you approach a Piece of Eden, may be illusions programmed inside your and your ancestors' brains. Despite all your and mankind's efforts, despite all the Assassins and/or Templars did to create a better world, you are still pawns to a megalomaniacal race that fancy themselves Gods. And as shown in Assassin's Creed IV: Black Flag, they STILL exist, either as Virtual Ghosts or as The Virus upon Mankind's DNA. The Matrix is real, and there's no escaping it...
Another (though just as philosophically horrifying) way of interpreting "Nothing is true, everything is permitted." is that on top of being no gods, there is no afterlife, no Heaven or Hell, no karma. Even some atheists like the idea of Hell, that there's some form of justice for the wicked. But in the world of Assassin's Creed, there isn't. You won't go to Heaven if you live a good life. You won't go to Hell if you do evil. Which even the relatively moral Assassins (compared to the Templars, anyway) can accept outright murder as a tactic - you can kill, and there's no eternal consequences for it; "Nothing (people believe about the immortal soul) is true, everything (a person can do) is permitted (by the cosmos)."
There are several occassions when Desmond relives "intimate" encounters his ancestors (namely Ezio) in the Animus... So if you think about it, Desmond has pretty much had sex with a quite few of his great-great-great-great grannies. That must make for some awkward conversations after he takes a break from the Animus. Also, could lead to some rather uncomfortable manifestations of his ancestor's "skills" the Bleeding Effect. Can you say "awkward"?
Also, there's the fact that an ancestor's story could abruptly end by having a child partway through their life, with that child being the person in the Animus's ancestor. This could make an unfortunately timed child stop a present day character from achieving a saving the world from Juno or some possibly greater threat.
Overlaps with Fridge Brilliance, there. No wonder Abstergo have had so much trouble finding Pieces of Eden, even though they have a massive advantage and big head-start in creating the Animus. Until as recently as the early 20th century, the average life expectancy varied little over the centuries between 20 and 40, which of course meant parents having children relatively early in life. With this as the norm, Abstergo and the Assassins are searching all of history for particular individuals who not only crossed paths with a POE, but who also didn't have children until much later in life than normal, or at the very least didn't father any descendants until after their encounter. Coupled with the fact that even knowing about POE would be dangerous enough to make your life a very short one, Abstergo and Assassins are looking for a needle in a haystack the size of human history! And one peppered with blunted, shortened and broken needles at that.
What lovely innuendo you've worked into that last sentence.
Some fans of the series wonder why Desmond would ever want to leave his life as an Assassin to become a bartender in New York, a much less glamorous lifestyle. Now, outside of the video games, why would anyone want to be an Assassin?! They only look glamorous because they're fictional characters in a video game where you respawn after dying! Jumping from building to building, murdering world leaders, and constantly being on the run from a much larger and much more powerful organization doesn't exactly sound like fun to me! One wrong step, and you're dead. And guess what? You can't restart the mission from an earlier checkpoint if you die in real life.