I wonder how much the characters will grow/change depending on your interactions with them. Although I always play good characters, I actually like this cast of "neutral-evil" characters but know that playing with some of them as a good character will net a lot of disapproval. But, a lot of these characters seem to have a lot of potential for character growth. Astarion, for example, has lived the past 200 years under a cruel tormentor and has possibly absorbed some of his tendencies in order to mentally survive. Now that he's free, perhaps with a good pc he can learn to see the world in a new light? Likewise, Shadowheart is secretive and seems unable to trust people. Maybe with a good pc she can learn how to trust and open herself up to honest friendships/relationships.
Ofc, there are some characters who I don't see changing, or at least not easily, like Lae'zel. But it would be a pleasant surprise to see if she can develop a slightly less callous/violent side.
Development like this could keep these characters viable in a good aligned playthrough while also adding an interesting perspective throughout since they'd still bring their own experiences/personalities to situations later in the game. After all, it can get boring if everyone is agreeing with you all the time.
