Regarding Wyl: DnD makes it quite clear that Warlocks don't have to be 'evil'. They can enter these kind of pacts for all sorts of reasons.
Also, well...one person's "normal" is the other person's "boring", I guess.
I think every companion should have *some* personal motivation or angle about them that makes them kind of unusual and their story interesting.
If you want blank slate personalities, the game might just as well allow you to create or recruit your own "silent henchmen" (I'd be surprised if they don't let you do that before go live).
That being said, not every meaningful companion needs to have connections to other planes to be interesting, for sure.
