Sorry, but I think what you just suggested would be boring.
You see, on a TM-track, skill can make a difference (and a big one). I don't see how skill would make a difference in a role playing game.
Therefore, many gaming hours should be rewarded with upgrades, giant weapons, in-game money and so on and so forth.
Of course, there must be a way to stabilize the economy avoid inflation, but I trust the creative minds of the QM developers as far as this is concerned.
I have a quest idea/quest system though (i don't know if this has been suggested before). Apart from the nadeo/npc-quests (if there will be any), there should be quests that one player can give to another.
Compare it with the Blue, White, Red, Black and Green nadeo tracks in TMUF and the custom tracks on TMX.
How to prevent those player-based quests from becoming repetitive? To be frank, I have no clue, it would probably contain a lot of grinding (and thus boring) content.