Noise From Rear End

[arehm]

99Z, mostly stock 112k miles.

Been noticing a grinding like noise from the back end. Jacked up the rear end and spun the tires. It sounded like it was coming from the pads/rotors area. The passenger side inboard pad had a small angle worn into it like it was seated wrong. Pads were original and someone suggested they could be glazed.

I swapped pads yesterday and yes, the problem is more pronounced. The wear seemed even inside to outside pad. On the inside pad there was a SMALL angle worn in the pad. Instead of being flat like this ______ it looks like this ______/. Now it's a SMALL angle and seems to coincide
with the very edge of the usable portion of the rotor. It's like the pad's just a 1/8th or 1/16th inch too close to the axle and rubbing where it should not. Everything seems right and there's no play with the caliper.

Are rear rotors different than front ones? I suspect so since I've got a spare set of front rotors on my shelf and that would be too convenient for testing purposes.

Could I be looking at a problem with the E-Brake? It works fine and stops the car (not sure how quick It should stop the car, seems a bit slow, but I didn't try a panic stop.

Suggestions?