Forget prerequisites for a second - you have a much bigger issue. I know of former med students/unmatched MDs who have gone on to become PAs/other midlevels, but they had really good explanations for why med school or residency didn't pan out (e.g., naïveté about the Caribbean, horrible family issues, etc.)
But your situation sounds much trickier. With the caveat that I know virtually nothing about PA school admissions and I'm only speaking to the obvious questions someone would have about your situation, you need to have a really good explanation for what happened with your residency. If your PGY2 professionalism issue was due to something correctable - immaturity, poor skill set, a health condition - then maybe you'll be OK. But if your essentially forced resignation was because you slept with a patient or hit a nurse, then I can't imagine any healthcare field is going to be open to you. So I hope for your sake (and ours) it's something like the former.
PA route aside, with one year of GME, shouldn't you be able to practice as an MD in many states? You won't get an academic/private practice group job, but I'd imagine you could hang a shingle somewhere. Why not pursue this route?
