Let me be the first to say "welcome." I would have to dig deeper into your specific model of Pioneer to better answer those questions.
Yeah, don't pair a VP100 with M80s. You will be disappointed. I've got a VP180 paired with my M60 fronts and it works really nicely, although I would have loved to try a VP160 instead to save some cash and for the different design, but the VP180 came out a few months before the VP160 was announced, and I was looking to upgrade from the VP150 to something else and made that leap. The VP180 is very impressive, but it is large.