An update on the door...
Discovered that the E-clip on the upper hinge pin was missing and that the pin had crept up a bit resulting in a hinge being a bit misaligned. I pushed the pin down and door is a little better, though I believe that there's still some distortion going on: it certainly doesn't close like it did when new. As mentioned, I'm just going to have to live with some of these things.
Dealer sent me a new fuel cap as a possible resolution to my water-in-fuel issues: I have drained everything I have, not completely, but enough to tell whether I have water in various equipment tanks and filters, and, of course, the Kioti's tank (pain in the arse to mess with the stupid band clamp with that recessed nipple!) and ZERO traces of water. BIG mystery as to how this thing is managing to get water into the fuel filter. Anyway, the fuel cap... the original one was always a pain, really cheap feeling, hard to get the key in to. New cap has a double-sided cut and you don't have to figure which side of the slot to slip it in to; a lot smoother. This is about as much as I figure the dealer is good for here. Loader and door are just always going to be reminders that I won't be buying one of these tractors again (never likely going to buy another tractor anyway, so it's not really saying that much).