I voted 'kill everything!' I can see that Larian would not want to do this though, since someone would latch onto it and it would be blown out of all proportion (I am not sure what rating the game has?). A pity, since having unkillable NPCs is very inconsistent.
It has an 18 (Mature) rating in the UK. Not sure about other countries. One of the many things I love about RPG's, they tend to be aimed at mature gamers which means for the most part, fewer of the "family friendly" nerfing/sanitizing pressures are present.