My issue with Shadowheart's name is not that it is self made, but so obviously and plainly evil combined with her general demeanor. She's shady and logically I see little reason to have her in my party. I probably will if I don't play a cleric tho, but I'll still give her the side eye :P
In summation, my issue with her is that she is immediately untrustworthy. That said, I do like the voice actress and I am curious as well to see how her own story will progress and the possible paths to take.
Well, so far we have seen 4 companions, and I wouldn't trust any of them; but if that's all we have to choose from, I could be persuaded to give any of Gale, Lae'zel and Shadowheart a chance. Not Astarion, though.
