But that only works at the shallow level. A crook can get around that by asking/bribing/convincing someone else to be the one who's responsible for the amenment.

There is very little outright corruption in Congress. Special interests exert most of the influence through campaign contributions that are publicly disclosed. Larry Lessig has a great book on this: http://www.amazon.com/Republic-Lost-Corrupts-Congress---eboo.... And here is the link to his TED talk on the same topic: http://www.youtube.com/watch?v=mw2z9lV3W1g

I wonder if Congress uses any sort of version control. The text of these bills are written by - staffers and sometimes lobbyists, so I'm not sure how it would work.