Who killed the man in the lighthouse? It's assumed that it's another Booker that failed.
How did Elizabeth get her powers during the closing of that tear? (I'm guessing that you are talking about the tear she goes threw when she's a baby.) She gains those powers because the top half of her pinkie was chopped of by the tear, meaning that she has parts of her body in two different universes.
How do the Letuce siblings get around without opening tears? Fink attempted to kill the Letuce twins by sabotaging the machine they used to use tears. Instead of killing them, he scattered them throughout the universes, giving them timelord powers. Elizabeth doesn't have these powers until the Siphon was destroyed.
Yeah. Most of the tear and time travel concept can just be explained with the *Magic!* excuse to fill in the gaps. Elizabeth
somehow gains her powers as a baby through that tear, being linked to another world through a tear wouldn't necessarily mean the power to access all worlds or even give Elizabeth her powers in the first place. Though the game did give a somewhat satisfying answer to how it all went, and it would be quite difficult to think of something that would fit the story anyway. Aside from the game scenes the audio logs were the closest we could get to detail.
I did enjoy the Letuce twins though, their scenes were made excellently. Kind of like... ah fuck. Forgot the characters. Anyone think of similar characters to them. Aside from Tweedledum And Tweedledee?