Matt,
In my process of 5/6 or so reinstalls the only thing I had to do to retain my save games and original user profile was copy the Command and Conquer 3 Tiberium Wars folder in the "roaming" directory.
All user settings, including video/audio/etc, as well as save games are included in that folder. Give it a shot.
Also, I got the game working just by creating a new user account, logging into that account, then playing the game. I didn't bother re-installing. I am curious, though, if I reinstall the game through the new user account will I be able to play the game through my current user account? I realize it's much less of a hassle than having to switch back and forth from XP, but IMHO there shouldn't be any hassle for a game whether I want to play Campaign or Skirmish...
Either way, thanks Matt, and EA Support!