You are ridicolously reaching
Astarion used to sell criminals to a clan of vampires for profits, which is a criminal activity.
Maybe you should rework your ability to be well-informed.
That being said he would make more sense to me as bard then a rogue, but not due to the reasons you mention, those are all non-sense.
The really big problem with Astarion is that he supposedly doesn't have a soul because he can't see his own image in mirrors, however he totally does act like he has a soul.
By and large I'm very happy with Astarion and he is my favorite companion so far.