I like the setup you propose, Arkane. Mega Man's total lack of a charge shot or rapid fire mode still feels like a major step backward to me. Even the first three games, which had no charge shot at all, have a rapid fire button in the Complete Works versions (and I assume in the Anniversary Collection as well).

After seeing Proto Man's major charge attack in Mega Man & Bass, I'll agree with you that a stronger buster would fit him far better. As far as the shield goes, I used to think that they got it backwards in Mega Man 9 ("he's shielded when he jumps!?"), but then I realized that it was the exact same thing in Mega Man 3...