#1: Yes.
#2: See #1.
#3: No idea.
#5: The Dharma Initiative was paying tribute to the Island's former inhabitants. (This is directly from Darlton's mouths)
#6: Who cares.
#9: Charlie was fated to die because...that's...fate? Why does it need a deeper meaning?
#10: Yes, it was meant to get Locke off the Island and find a loophole to come back, allowing MIB's plans to continue.
#11: Her husband died and she fell into a deep depression leaving her in the institution. Doesn't matter anyway.
#12a: The actor was a douche.
#12b: Alex.
#14: There probably was an answer to this once upon a time, but he grew up too fast. Doesn't matter now.
#16: Aaron was never important. They answered this in season 3, the psychic was a fraud.
#18: See wall of text above.
#19: The Island did it.
#20: Probably nothing. The point is that, to do so, the Island would be destroyed. And that's bad.
#21: Question rendered irrelevant by the fact that there's not really a sideways reality to speak of anyway.
#23: Ben led a coup against Widmore. He couldn't kill him at the time because of Jacob's rules.
#26: Ben made those decisions. Jacob brought in people through his magic powers, Ben recruited people for his own purposes.
#27: No idea.
#28: Jacob's rules.
#29: Seriously irrelevant.
#31: Dharma station that was to be constructed? Who knows, not relevant.
#32: I'm thinking no.
#33: A method of controlling the hatch inhabitants. Probably inspired by Smokey's claiming.
#34: He's a liar liar liar.
#35: Irrelevant
#36: Yes.
#41: Vincent ate him.
#42: Sayid described it himself: he just didn't care anymore. He lacked an internal drive, really, and was content to do whatever he was told.
#43: He turned human after the Island was deactivated.
#44: No idea.
#45: Really no idea.
#48: No idea.
#49: Jacob's rules.
#50: MIB I'd wager.