BTW, g_maxGameClients is the number of people who can actually play in a game (not just spectate). You don't need\want that in the command line.
Make a shortcut to either jampDed.exe (if you are hosting a server for others to play on and want maximum performance) or jamp.exe (if you are hosting and playing on the same computer, not recommended except for Solo Game). In either case, right-click the shortcut, add
+set fs_game xmod +exec server.cfg +exec xmod.cfg
at the end after the quotation mark, save and close.
Use the shortcut to jampDed.exe to launch the dedicated server (you will see only a console) or the shortcut to jamp.exe to launch Jedi Academy multiplayer, then Play Solo Game or Create Server as usual.