>...or do I just have OCD perfectionist tendencies?
That might be true if it was scuffs and scratches on your photos. The only right answer (for you - I think) is that if normal use of your D7000 inevitably results in the camera appearing to have been used to take photos, then the camera is most likely being put to good use.
On the other hand, if the time needed to replace the rubber grips (there's no way to buff them) detracts from the amount and quality of time spent making photos, then the camera is likely not being put to good use.
Personally, I can't stand the look of a new camera. I much prefer the look of a camera body that appears well used. That well used appearance invariably means that I've spent enough time with it to get to know its quirks, idiosyncracies and picture making qualities.