but I can tell you now that it was propaganda.
No doubt about that. Fahrenheit 9/11 is a propaganda movie, and it isn't meant to be anything else. However, propaganda is used from the government as well. Michael Moore was critiziced for showing only peaceful pictures of pre-war Iraq in Fahrenheit 9/11, causing the false impression of it being a happy little country, and not a dictatorship with an oppressed population. However, Moore wrote in response that everybody knew about Saddam's cruelty already (which again is something US propaganda never failed to point out).
Moore does make "guesses" about Bush's thoughts and of course these are no flattering guesses. However, you won't find any wrong fact in the movie that can be checked out, otherwise they would've skinned Moore alive. I did not like everything about that movie, but some of the facts he brought up are sure worth to be taken into mind.