AgentBirdnest: MMB, my friend... I switched the "Action" button to MMB back in '07, and never looked back... I love having "Fire" and "Action" on the same hand :-)
Q and E are for leaning (which nobody ever does...)
Ever played Thief (the original)? Leaning is extremely important there.
tinyE: I saw an episode of Myth Busters the other day where they tested the movie myth of shooting open doors by hitting the lock. Not only could they not get the door open, but using a professional sniper they couldn't even damage the lock. XD
Eventually they used an elephant gun which worked but they were quick to point out that you never see Bruce Willis carrying an elephant gun in any of his movies. :P
Interesting, and logical. I guess you could harm a lock with a bullet with enough power in a way so that the lock gets permanently stuck. Would need an RPG after that, only that, in most games, they can't even harm a curtain.