If you think all Evil creatures are in cahoots then you've got a very narrow understanding of alignment. There are plenty of reasons a Chaotic Evil character might join a crusade against demons.The problem with most APs is that they are not made for evil characters especially Wrath of the righteous. I mean what reason should a chaotic Evil char have to join some crusade against demons? If they really use it then there won't be as many role-playing options like in Kingmaker
No, but even the first book of the AP says that the whole thing is made for Lawful Good chars. One of Kingmakers greatest strengths was that it worked for characters with all alignments I just don't see this working here.
There are also the AP mass combat feature which works poorly with RTWP