I did not read everything above, so just my 2 cents:

- I met Karlach and from her dialogue it looks like she really is a companion.
If you do not speak with the dead you do not know the paladins work for an archdevil, so there is a good chance players kill her without ever knowing she could be a companion.
Well, she is less hidden then Nordom from PST for example. ( did anyone find him without a guide ? )

- Any idea why Minsc is still alive after 100 years? He is human and no archmage or another big power that can axtend his life.
Don´t tell me he has a toadpole too, there is no brain to be eaten ;-)

groovy Prof. Dr. Dr. Mad S. Tist groovy

World leading expert of artificial stupidity.
Because there are too many people who work on artificial intelligence already :hihi: