maybe adding a bouy "reset" every hour or 2 to RP the main fleet elements (NPCs) coming and kicking the stuffing out of the invading force?
I like this idea, don't write it off right away.
I know Freeworlds does a lot with base conquering and all that, they might be more interested in this then we are.
also, make sure you edit a backup file so you don't get kicked/banned for cheating. finally, Igiss has said that you need aproval from him to modify the disco mod and use all its contents as your own for your own mod/server.