you shouldnt need to make new meshes... the whole world is already meshed. if you want to fight in a certain area drop a "grind" marker in that area and set the content ID of the monsters you want to fight. making a mesh is pointless. or you can put a level range if you are leveling.
Donations are voluntary.
You are not buying by donating.
If you find a mesh error, please make a proper report in Mesh thread