Recently, I've started hearing a pulsating squealing, so I took it to firestone, they said that my rotor is unbalanced and is too thin to get machined, so when I brought it home that day I popped my tires off and checked my brakes, it looks like my pads are in contact with my rotors, is that normal? I thought I would see a visible gap. Additionally, I still saw about a centimeter of my pad left on both pads and both sides of the car. I've read that these semi-metallic pads often make squealing noises, but I just don't want to damage my car, what do you guys think?