The interaction skills.
Empathy feels like it's necessary for your first few playthroughs but Its also feeling like something you might be able to drop later if you just memorise who likes and hates you.
I will say I do miss the learning boost for having the other skills in the same tree that we had in Long live the Queen. (Its probably a balance thing but I liked the way you could use it gain additional points or offset penalties when you really needed to).