sure I love good creative work - and I am sure the motivation of being able to share something with the universe (if good enough) would definitely be an extra bonus (maybe somebody doing that could get a badge for it and some kind of recognition )A good idea there will be a check obtuse XP and players can create show how good their imagination is. Also maybe if the missions are good enough they could be expanded and added into another ship level or planet.
This worries me a bit "Power corrupts absolute power corrupts absolute".
If you don't mind player-created missions that can level to max level in one day. Then ok else I would not have them.
Just my 2 cents
well, then maybe how about a different aproach?
you don´t get xp for killed enemies but for the time, which is needed to get through the mission while the mission has a minimum of enemies which need to be implemented (so nobody can create an empty mission to get the xp easy). And that time is calculated by the size of the map (like the overall lenght has a calculated average time and that is the base for the xp . In that case nobody can fill a map with minor enemies to farm or other way around
say are you and Odee both work in the Cosmic Business - your texts always stand out of the mass