I just did the same repair on my Sub-C, rotor screw broke off in the automatic winding plate. I've had my Sub for about 3 years now but this would be an issue with the 2836 inside, nothing to do with the Submariner and could have easily happened during rough shipping.
As far as the other problems with your watch, I have noticed that the bracelets seem to be getting a lot worse on these watches, have had several fail, lots of tight links. Overall, I agree that the quality seems to be going down, makes me hesitant to pull the trigger on another watch.