Stick to the movie, folks. It’s a first novel. Seriously, this is like reading a draft. In the intro, Palahniuk says that he didn’t know what he was doing, so he just shoveled everything he could think of into the story.
The bones are definitely Palahniuk’s, but the flesh that makes it human came from Fincher/Norton/Bonham-Carter. The director did an amazing job cleaning this up for the big screen, and Edward Norton and Helena Bonham-Carter filled out characters that are really quite faintly sketched.