@Rinrynque
1: You can modifiy some map things like boundaries, vehicle positions etc., and change the location/number of vehicles. Though it's also possible to add planes from older BF titles.
2: We don't provide any server files (neither did NoFaTe reverse-engineer any), you'll have to get them on your own.
3: On Linux 512MB RAM and 50kbit/s per player I'd say