I was reading #4, the part about feeling no need to change.
This doesn't directly relate to what you're seeking, but the thread reminds me of a acquaintance I had. I once did something professional for him for a fee (minds out of the gutter, please), and offered him a future discount.
He told me that he had been diagnosed as a sociopath, that there was no abuse in his childhood, but I think it was in his late teens that he got the diagnosis, and when I knew him, he was in his mid-twenties. He said that he'd had to work to learn empathy, and he warned me about making concessions for him because his go-to was to take advantage. So I thought it was interesting when you mentioned not feeling a need to change. This guy chose to make changes, and even though his wasn't as naturally motivated as others, he showed me respect, honesty, and consideration that naturally empathetic, non-sociopathic people have never shown me.
Part of that is because it's not in the U.S. culture to act that way. I'm that way, but it was partially natural and partially learned. I lean toward honesty and directness anyway, and when I hung around with a German, I noticed that was her go-to, and so I emulated it. She said: "If I tell you what I think/feel, then you have no reason to guess." It may be abrupt, but I feel like everyone is safer if we're direct and honest with each other, and imo/experience, that comes from intention as much, if not more, than empathy.
The sociopathic acquaintance acted with intention, and if I recall, it seems like we discussed that he benefitted from better relationships for making the effort to make up for his lack of empathy.
Also, you may have heard this before, the story can be found online, I just don't remember the specifics. There was a doctor who was researching psychopathy, and all of the brain scans were coded for anonymity, including his. He was studying one of the brain scans of a psychopath and came to find out, it was his own. He was surprised. So I think, based on what I recollect from that story and my limited knowledge and experience, that just because one has the traits or that kind of brain, does not mean they necessarily go to the dark side, are anti-social, cannot be altruistic, cannot have meaningful, close, and safe relationships, etc.
Empathy can actually kick someone's own ass, especially if it's hyper-developed, such as people with an abuse history who become co-dependent. They have a hard time filtering out other people's stuff and defining the boundaries between where they end and others begin.
Again, nothing to do with your questions about ctb. But I do find this an interesting subject.