I think Ben knows how everything goes down in the past because he has some reference to the future (either because he's been there, from there, or has information from others who have)....though he has seemed surprised on a few of occassions: (1) when that dude killed his daughter and he said "they changed the rules" (2) after Locke told Ben that he was going to see a woman named Eloise and (3) when Desmond showed up to Eloise's church and said she was Farady's mother. Otherwise, that dude has known pretty much how everything goes down and has encouraged/manipulated people to make sure it goes down the way he's been told or knows it should.