"And also, do you notice how he keeps asking Amber to talk about her "suffering"?"
Not surprising. He has lost control in his "real world". This is the only place he can feed his strong appetite for power, control and admiration. One reason some folks enjoy the suffering of others is because it makes them feel powerful and important.
Another possibility--once again, attributable to a poster on WS--is that Scott wanted detailed descriptions of her emotions b/c, as a psychopath, he is in a continuing process of learning how to mimic the emotions of real people, and wants to learn all about the "subject matter" he is "studying".