Cut the fat so you're left with what's mentioned
here (don't forget to enable the console, though.
) If you wish to earn achievements, you'll need to start the game anew.
Edit: Skipping the intro videos is also fine, as is, I imagine, adjusting the fov. Ditch everything else to be on the safe side.
Edit 2: Actually, if you just add +exec rageconfig.cfg to your Rage launch properties, you won't need the console, so you
should be able to use your existing config - minus the enabling of the console, obviously - just fine (you'll still need to start a new game for the purpose of earning achievements, however).