The Queen.
Ron Weasley was on the knight and was attacked by the queen.
A meteorite
Professor Quirrell was jinxing the broom trying to make Harry fall off. Professor Snape was trying to keep him on it.
Stone's Fall was created in 2009.
Stone's Fall has 608 pages.
In the game of chess, a pawn is a 'man' (piece) of the lowest value, therefore if you say someone is just a pawn means his place is not important in the scheme of things. It also implies that he has been manipulated. When Oswald was arrested after President Kennedy was shot in Dallas, he claimed he was just a "patsy" or fall guy; he could have said, "I'm just a pawn."
Corner Stone
Yes.
Harry has to fall through Devil's Snare.
both will fall at the same time
you tie it to a piece of string
a piece of pie