Waleed Aly slams Port Arthur massacre film maker, page-530

Very chilling. That "cheeky cheery disposition" in Iwonder's post and your list sends icy chills down one's spine following so closely together.

Psychopaths are notoriously difficult to either treat or even to be identified unless written reports and enough people come forward to report these to psychologist. They can't be medicated effectively. They have a personality disorder of the most serious kine and notoriously difficult to interact with.
Empathy for others and behaviour consistent with that empathy is certainly not apparent in their thinking.