Completely remove the ****ty observer mode system.
Enforce a 'Trial/Classic Playercount' limit on developing servers. This way you could have a certain of amount of Classic/Trial's log on and develop for the server without having to pay to develop. Obviously Hosted would up this cap as a benefit for wanting to reach that status. Classic/Gold status would completely remove this cap.
As for the payment thing.
I honestly doubt that there would be any payouts that would make it feel like developing a server was worth it anyway and unixmad would probably place ****ty rules on it as well being the greedy bastard that he is.
If you want to make money go make a App or get a job, I don't see Graal being anything more than a hobby platform to quickly prototype your multi-player ideas.