You may find your 80-90% movies/games and 10-20% music habits will change after you get your Axiom speakers. I built my system figuring on those percentages, but found that having great sounding speakers has siginificantly increased my music listening. My M22's are fine in a room larger than yours, and I wouldn't trade them for M60's because of space restrictions. However, I do frequently lust after a pair of M60's.
I run a VP150 for the center and don't think it's "too much" although it was turned down 2-3db more during setup compared to the rest of the speakers.