could be bad rotors, or brake pads wearing unevenly, which would result in bad rotors.
bad rotors
Bad bearings inside or loose castle nut.
It would be highly unlikely.
If you have a pulsating on stopping is an indication they are warped. They would have to be checked with a micrometer to tell if they can be resurfaced.
Yep.
There is a pulsating on braking.
There will be a pulsating on braking.
Grinding
You either have a bad brake caliper or the brake hose is bad.
Bad rotors
Is it accompanied by a shuddering or vibration? You could likely have bad brake rotors.