rfactor\rFm dir: contains rfm files which define the mods. Client and server rfm files must match exactly. I made changes manually but once configured to taste, rfm files should be left alone.
rfactor\UserData dir: contains profiles (directories) used by the dedicated server. Profiles can be used by servers or clients, but the client install only needs one for the player; it does not need the server's profiles. launch.bat will place a new track list in one of these directories every time the server is run.
rfactor\UserData\xxx\modname.cch contains player (profile) settings for mods. Some of this info (StartingCash, startingExperience) is initially read from rfactor\rFm\modname.rfm and after that is only maintained in the cch file. Car ownership is maintained in the cch files. To reset the cch file to mod defaults, simply delete the cch file in the profile dir and it will re-initialize from rfactor\rFm\modname.rfm.
"for anything offroad, don't use stability or traction control, but do use anti-lock brakes."
rFm file changes:
DriveAnyUnlocked = 2 // makes all cars avilable in MP, but car still needs to be owned to buy upgrades
MusicDir = MUSIC
StartingCash
StartingExperience
rFm files on client and server have to match exactly.