Spoke to Maria at Rohrbaugh on Monday, and gave her the details on my pup. I referred her to the pictures in this thread, and she advised that she'd pass the information on to Mr. Rohrbaugh.
Maria left a message for me today, saying that they had reviewed the images, with the following findings:
1) The metal flakes encountered at teardown are from spent round brass, and are nothing to worry about.
2) The wear on the frame is caused by the barrel impacting the frame, possibly made worse by brass fragments from shell casings.
3) Their advice was to change ammo and not worry about shooting the gun.
I left another message for Maria today, just asking her to confirm that they reviewed the picture of MY frame, and not the picture posted by IDP. In my estimation, there is a huge difference between the two - IDP's wear is normal, and nothing to be concerned about. I still want to hear, from the factory, that my gun (with the dimpling on the frame) is safe to shoot.
I am, unfortunately, somewhat disapponted with Rohrbaugh's customer service. Maria is kind enough to return my calls, but she can only relate the information given to her by someone else. A five minute conversation with Karl Rohrbaugh (or someone else with manufacturing and firearms knowledge) would go a long way towards easing my concerns.