its possible to even add your own weapons and monsters too but youd have to know abit of java or c++ and maybe some 3d rendering depending on what the server uses to run itself, when i was making the roleplaying ai package the server was created in java so i had to learn a bit of java to make it go, took me a couple of months to get a working beta version but it worked like a charm, you could even change the map aswell but thats alot harder, if the swg server has a gnu license im pretty sure theres some kind of restriction to what you can change or not change but if it doesnt then you could probably do whatever you want to it until soe catches wind of the server itself