That's a very cool theory and it makes a lot of sense. I like the Willoughby!Remus idea particularly other than the fact that I see Remus' reasons as slightly more noble than Willoughby's. After all Remus knows that Dumbledore would get owls trying to force him out whereas Willoughby is ONLY thinking about himself.

Then again I'm afraid for all my liking of bad boys normally I've fallen for pretty much everyone of Austen's heroes over her villains.