Altair didn't die in Bloodlines. The details of Altair's death are completely unknown to us, and is never revealed. The only clue given is in Codex Page 30, in which Altair describes his realization that he's soon to pass away, and appears tempted to use the Piece of Eden to elongate his lifespan. Whether or not he did is a mystery.
No.
Altair is the dude in Assassins Creed
Altair is 25 in the first Assassins Creed game.
Yes
He is altair
Assassins Creed Bloodlines is 5 weeks after Assassins Creed 1. This is what happened to Altair before he dies. Assassins Creed 2 is a completely different thing. The main story is the same but the story of the main characters, Altair and Ezio, are very different. Assassins Creed Bloodlines does not have the Animus in it as much as Assassins Creed 1 & 2
yes
no
no. only his robes as an outfit
altair
in assassins creed 2 when he meets his uncle
Most people say that Altair died when he jumped into the haystack in assassins creed 2 when Desmond has the memories about him.