Re: the lightsaber duel argument....is anyone remembering that Vader doesnt have real limbs, therefore cannot produce sith lightning nor do any flippy-floppy stuff? And that in ESB he doesn't want to kill Luke anyway, and probably was pretty reluctant to in ROTJ too. And ol' Papa Palpatine can, to quote Paul Atreides, probably "kill with a word" anyway.
So ner!
:-)