I think that as long as you follow the manufactures guideline for replacing the springs and proper lubercation, that you can shoot the Rohrbaugh just about as much as any other wel made firearm.
I'm not so sure that the R9 would withstand 100,000+ rounds like a 1911 or certain other larger pistols, regardless of how well you maintain it. Because of its size the gun takes a bit of a beating which is why +P ammo is not recommended.
The highest number of rounds through any single R9 that I'm aware of is around 5000.
However, it was never meant to be a range gun that digests huge amounts of ammo. Its only mission in life is to be carried for self defense purposes. Once you're satisfied that it's reliable, there's really no need to shoot it much, other than an occasional test firing of a magazine or two to keep yourself familiar with it.