I'm hoping for some input on the level of disadvantage it would be to require a unique skill for every power used out of a VPP. This would seem like a good solution for magic. The specific structure would be that every "spell, combination of power/advantage/disadvantage/special effect, would have a unique skill for that combination and only that combination.
Possibly with complimentary skills. i.e. "Fireball" skill having a complimentary skill, KS: Fire Magic?
(This might seem convoluted but magic in the Hero System has never worked right for me.)