1. I won't even bother arguing about this. It's petty.
Lacking parental care at young age, being raised in an unstable environment, being mistreated, bullied by peers etc. and/or surviving some traumatic experience that leads to desensitization, all this in itself is what creates a sociopath.
And the biological factor (genetics), especially when combined with mentioned above, creates a psychopath.
But none of that creates a serial killer. There is something else (assumingly connected to self esteem issues) that creates hypercompensation in form of exerting power through destroying things/people.
"Normal", usual psychopaths don't have any self-esteem problems.
2.No, I don't mean that they're just law abiding citizens.
I mean that they are full-blown sociopaths who use their sociopathic traits to benefit society.
A surgeon who is as cold and unempathic as only a psychopath can be, and who basically views his patients as broken mechanisms. But who is very good at repairing them.
A buisnessman who is ruthless and calculating, and who actually despises his employees, but is absolutly brilliant at organizing them, and makes profits that help to feed their families
Guys in the military (who actually are a part of recon team, which means that they are the the first to make contact with the enemy) Who kill people on regular basis, and as far as I know kinda enjoy it...
They're praised as heroes. Of their country at least....
So there are areas where sociopathic traits are actually good.
You know what I mean now?
3. What you are reffering to is just a textbook example.
No real psychopath thinks that about himself.