Maybe this sounds controversial, since I haven't found anybody else complaining about it, but I really dislike this feature of the old MOH games, where if you stand in some terrain that is sloped, say a hill, an impact crater or rubble, and try to move, you will slide down it as if it were covered in butter. This is really annoying because for example, if you try to take cover behind a pillar and there's rubble around it, you'll just slide off and expose yourself to enemy fire.

Is there any way to disable it?

Not controversial at all, it just seems to exist on purpose imho. There are some friction variables serverside so you can't change it from your side.

I'm playing the single player campaigns. Not really interested in multiplayer. So if there's some command to disable them I'd really appreciate it, even if I have to type them in on every level, since I could just bind a key for it on my autoexec.cfg just like I do for adjusting the FOV.

sv_friction - global friction value for the world (default 4)
sv_waterfriction - the fricition when inside a water volume (default 1)

sv_gravity doesn't seem to help a lot

i didn't try them in SP but the sv_ prefix leaves poor hopes

here's a doc for some variables: www.moddb.com/features/fakk-2-configuration-variables-cvars

Thanks for your help, but unfortunately none of them seem to do anything, except for sv_gravity, which only makes NPC's fly away when messing with it, which is pretty funny. Welp, guess I'll just have to put up with it :P