There isnt a rank hack... There are already a few topics saying that.
my bad, i searched and didnt find anything. Do you know of any modded servers? I remember WaW had some where it was SND But you can respawn, and you would just spawn trap one team and get lots of xp, than after "Donating" 200 deaths or so, you may switch and get kills.
Ranks are not server sided, if you disable steam cloud it will state that anything gained will be for this PC only and will have to re-do it on another computer. Its running the same kind of system as MW2 did but does not store them in the same place, Im sure someone will find a way eventually.