so... update: installed new pads.. went to bed them in, got back. drove to work next day, drove home...
I noticed the rotor on the driver side is blueish, and stupid hot. I spit on it, it sizzled like spitting on a hot coal. Brake pad is dragging.... what would cause this? I noticed it had a slight touch with old worn pads as well.
I also found out that mid year through 05 mazda switched brakepads and design, and used thinner pads on newer models. I think the pads I got were for the older generation, and mine used newer thinner pads.
However, rear left is dragging, rear right is not. In fact, it's perfect. My concern is whether the rotor on the dragged pad is toast or not. It was blueish color when I stopped (I left it in gear, no ebrake for that reason) and haven't seen it this morning yet.