We use our sunroof all the time. The cable that operates the front one is broken, so you have to push it up manually, but no other issues. I did just buy an '02 VDC that someone has glued the front sunroof shut, but it only has 120k miles on it, so it's been sitting a lot, so I'm guessing the drains are clogged. I will be cutting it open to try to remedy it correctly.
I've not had any relay issues.
A lot of variables for mileage, but that sounds about right. I don't calculate mine, as 90% of my miles are in town.
I hear a lot on the internet about an oring in the fuel pump assembly that swells, and cracks the tab on the metal cap it's under. Dorman even makes a repair kit for it, now. I've not had an issue with it, but we have fairly low ethanol content up here.