brake and tire wear problems--related?

[uunter]

Backstory:
18 months ago my brother bought a 2001 Mazda Miata MX-5 that was in great shape and had low mileage. A year ago, he pulled a dumb stunt that we were lucky to walk away from. The repair involved a new wheel, a pair of new tires, a new steering arm, and an alignment (but amazingly, the axle was spared), after which I bought it off of him. My first Miata, and I've fallen in love.

The symptoms:
I quickly noticed the right rear tire wearing more quickly than the other three, and started reading through AF forum posts. I was worried it was an alignment problem that was too fundamental to be fixed. But the wear was even across the tire itself, so then I suspected the brakes. Eventually I also noticed that there was a pulsation on the brakes, and that there was a scraping sound coming from the right rear wheel that increased in frequency with speed, which supported the brake theory. Similar posts suggested a warped rotor, although I didn't see others reporting tire wear like mine simultaneously.

Troubleshooting:
I jacked up the rear to look at the brake system. With only the wheels off, I didn't notice any obvious source of the problem--discs and pads looked good; calipers and lines were in great shape. I disconnected the e-brake and test-drove it--no change in symptoms. I was thinking it might be a sticky piston on the caliper, but that wouldn't explain the pulsation; it would be a continuous brake pressure.

When I got around to actually taking off the calipers and rotors, I discovered that the inside of the right rear rotor did indeed have distinctly uneven wear, as well as a faint imprint of the pad. I found this article online, which seems to describe exactly my problem. Seems like in the accident, the pad cooked onto the rotor, creating a permanent uneven deposit on the rotor, which has gradually been exacerbating itself. I also found a broken clip on the caliper. Not sure if that's significant.

Questions:

1. That article seems to suggest that because I've been driving with this problem for a while, if I just resurface the rotors, there's a high risk of the problem returning due to remaining cementite, so I should just replace them. What does the AF community think? I see Duralast rotors for just $18 at AutoZone, but I have a feeling nobody will recommend those.
2. The pads all look good and have plenty of material left--any reason to replace them?
3. I got a new hardware kit to replace the broken clip; should I replace all the other hardware at the same time?
4. Does it make sense that the brake problem would cause the tire-wear problem, or should I keep looking? (I just replaced the rear tires, so I'll notice if wear is still uneven within a month or two.)