I don't think we need signups for moons. That would be a bit silly. Just...use discretion in your levels. If you don't have a situation where the player should be awarded a prize like a moon, don't feel obligated to put one in.
Fair enough, notmany people would want to use that many Moons anyway (I think). They would probably be best suited for bonuses (obviously) or just before a really tough boss (where one would lose a lot of lives).
Its a hack, it doesn't need to have 7 moons exactly, the only requirement for a moon, as mentioned by other people, is after a huge objective or before a boss and such. There should be no such worries.
well i think it would be good to have a "Hidden Items" topic, and moons and dragon coins would be part of that.
I like using one moon per level, because its makes completionest go back and look for stuff.