The Garth episode war airing on German SyFy earlier. I hadn't seen it in ages so after watching it again, I now have two theories regarding Peters:
1) It is just one big piece of performance art by him, living his "role".
2) To compensate for his total lack of acting abilities he has inserted himself so deep into the role of Garth of Izar, that he has "turned into" Garth of Izar.
It's just uncanny how much his persona resembles the one of "his" role: delusional, believes himself the ruler of the Galaxy (or of Star Trek in Peters case), has followers that don't question him, is willing to sacrifice people for his gain etc.
In either case I think Daniel Day Lewis would take one look and say, "Dude, too Method."
