5hole,
Welcome to the forum, and I'm happy to read your R9 is behaving itself.
Frame wear: There have been several threads over the last year on the condition you photographed. My R9 shows the same wear, and after 600 rounds I've stopped worrying about it. The abrasion thru the anodized finish alarmed me at first. Other forum members posted similar photos. The condition seems to stabilize after a couple of hundred rounds. And Karl Rohrbaugh has been quoted as saying the wear is 'normal'.

Just keep it clean and well lubed, and you should be okay.
Steve