Re: VPPs adjusting MPs
Well, if the GM allows it, it then becomes legal. By strict rules-as-written, however, buying a naked advantage in one framework is not legal, and using one framework power to modify another one is also illegal.
HOWEVER, IIRC, there is a way to use Aid to add advantages to a power rather than simply adding more dice/points. Not precisely sure what it is though, but I think I read it somewhere. Since that's not quite a direct boost in the way a naked advantage or just +xd6 EB would be, it might be permissible.