I think you have a wrong impression how the game server may look like.
I am sure that the gPotato Rappelz version runs on several server at the same time.
e.g.
One server just for the Login. ( AAA Server)
One FTP server that is used for the Game-Updates
One Server that runs the main Game.
One Server is used for HTTP (CS-Shop, ingame Guild View)
Maybe several DB server.
The Game Server runs just the pure Game. To reduce all kinds of Lag is it important that nothings else runs on the same server.
So the Game server will never run a FTP Demon.
The Game Server may run in an
DMZ. So GM PC's run in an normal Company LAN and aren't reachable from the WEB. The OAM ( = Operation and Maintenance ) Ports of the Game Server are just reachable from the save side of the DMZ.
Just the ports for the game data are reachable from outside.
So you are maybe able to hack the FTP server , but this one contains just the public files.
Don't think it is possible to 'hack' the Game Server so easy.
The only chance to get the files is, if somebody from inside leaks the files.
e.g. if they disband somebody and this person has all the data on a usb stick in his pocket.
Or if they store the data on a unsafe location.
e.g. they have to send the data somehow from Korea to Ireland.
so the game files may be saved for a short time on a public FTP server
Good Luck if you want to try to get the data, but I think it will be a waste of time.