I find it hard to make an argument to let someone into my group, who tried to kill me. I mean at best, he is impulsive and acts rashly, at worst he is a murderhobo. And in Astarions case it turns out both.
I would love, if that scene would get a change. Make him mistrustful, maybe even have him draw the knife for protection, but not outright attack the pc. Astarion could do with a bit of common sense, he seems to be all over the place.
