I kind of agree that there is no satisfying way of going the evil route, and I want to use as example of that issue the way we interact with Evil Queen Lae'Zael.

There is little to talk about with her. She is by herself, she's strong and independant, and only accept to be part of the group because we are a means to an end.
BUT
After successful battles, when she notices that not only do we hold our own, we don't even go down, but sometimes we DO get her up, she doesn't pick up on it. She doesn't seem to notice our martial prowess. When blatantly ignoring or outright despising the problems of others in order to prioritize our own need to get that parasite out of our skull, she doesn't seem to notice either.

I think there is something to say about things that affect our relationships with companions that aren't either:
- dialog
- good/bad decisions

I think combat could be taken into account. Maybe our level of strength/dex/constitution and how often we pick those in discussions? How often we fall to traps and so on and so forth...