Your distinction between selfless and selfish actors is interesting, because I reach the opposite conclusion. In my opinion, the most dangerous and frightening people by far are those who sacrifice in order to hurt others. Most people are selfish. I can understand them and I can deal with them. If I need something from them, I just have to figure out what they would want that they value more than what I want, and arrange a trade.

I can't understand your last paragraph at all. I'm not sure that free will is even a coherent concept, let alone a real thing, but I also don't see how one can possibly live without assuming it.