Fair enough, I also trade out Shadowheart for Jaheria in the late game but if we are talking about party support I wouldn't trade either for a Warlock.
Again, Wyll loses out because of his class and the 4 person party - not because his EA story was bad. If they had expanded the party they wouldn't have needed to revise his story.
No, that is not what I meant. I prefer the druid because I like their spells & summons more, as an offensive spellcaster. I don't bother with support roles, the cleric / abjurer would be an exception, because I am a bit curious how warding bond would work with arcane ward. But because I prefer offensive spellcasters, I'd take a warlock over thief. You can build powerful combinations with either, but the 3 levels of thief is just more boring to me.