I thought that the films were identical to the books up until the end. The screenwriter changed the ending. Regardless, I think it was an acceptable change and I thoroughly enjoyed the movies.
No way, so many problems with the timelines and stuff. My biggest problem was with the personal shield. The slow and steady blade my ass. The actual fighting when the shield is used is fast an furious and definitely not how it's described in the book. Plus his sister is not born and she never creeps out the Fremen and doesn't kill the Barron.
I was hoping that the movies would include Fade having to kill everyone in his favorite brothel to please the Barron. If we want to have a scene where we discover Fade IS a monster too, that would have done it.
Right the ending of part 2 is where the veered off from the book. It's been a couple of years since I read Dune so I don't remember much about the combat.