I don't think companion approval or disapproval has anything to do with good vs. evil, but rather it is a metric of how they perceive your actions. I doubt they could act like a moral compass anyway, since they fall between evil and neutral themselves. Shadowheart will try to murder your character herself, depending on the choices made (and so does Lae'zel). It's a bit ironic, because you can order Astarion down and he will obey, no rolls involved, but fail to persuade Shadowheart and for the knife she goes.
False. The characters have alignments and they are between neutral and evil. You can connect the dots. I said game not the characters btw. Not to mention they each give questionable reasons if you talk to them. Laezel tells you she enjoys cruelty and Astarion was always a bad idea. Shadowheart does not like vampires and thinks that he was a liability I think. Gale approves of anything that furthers his goal even if they are dark. My guess is that he saw him as a dangerous tool. Wyll wanted to make him a hero despite Astarion clearly stating Wyll is the tasty one. Just a few examples.
Astarion does not obey anything not to mention ncps can lie. Shadowheart has her reasons and so does Laezel. Based on in game scenes and datamine. Not really going to talk about those due to spoilers. You are in for a surprise if you think you can change Astarion without playing as him is all I will say on that. Shadowheart is soft. Laezel though....she is not that bad and can be swayed if you play like a leader but the degree to which she can be swayed is in the air.
My point is on removing companions though. Not where they end up or how some perceive him.
