GM Scrolls

The prereqs most likely won't stop hardcore questers like Isaac, dan, and a few others (and me!). Not to mention this sounds like self-gathering Dragon Spirits/Scales all over again. Hoo boy.

Personally I don't think there really should be a an allowance of GM scrolls in general. Good for crazy events, maybe, but not anything else.

I'm sure they could manage to make a hard quest. Of course nothing stops hardcore questers!
The quest should combine Jump questing(This kills a lot of people right there), Knowing a lot about Masteria(Go die non-readers! ), getting a lot of quest items(1k items please) and some puzzle-like thing.

Then make some kind of jump quest+boss thing, the boss would do low damage(1's) but would try to make you fall, if you fall, you have to do the collecting quest again.

Once you kill it you have 5 minutes to get out of a dark jump quest room(Think entrace to dark magician's lab) or you lose and have to do the collecting again! Mwahahaha.

Then you can use the exchange quest, but now you have to get the exchange items! Which should have lower rate than badges, and be in a jump quest like map, you fall, you fail.

I think that would be enough to stop most people.