Rear brakes are always an issue on the 800. I've found that a lot of problems with these is the guide pins on the caliper carriers which seem to seize up. Periodic removal and greasing is essential to allow the calipers to move freely and allow the self adjusting mechanism to work correctly.
Also, looking at the pictures of the hatch, there is some colour shift near the edge. My Zircon 800 had the very same effect, perhaps due to the stressing of the metal when being slammed shut. It wouldn't polish out.
Sadly she's no longer with me but had 303,000 miles on when she went.
