There is a pulsating on braking.
A pulsation when braking, and a loud screeching noise(pads also gone).
Yep.
There will be a pulsating on braking.
Grinding
could be bad rotors, or brake pads wearing unevenly, which would result in bad rotors.
Bad rotors
If you have a pulsation on stopping the rotors are warped. They will need to be checked with a micrometer to determine if they can be resurfaced of discarded. The government set the regulations.
No just the bad one.
what do brakes look like when they go bad, how far can rotors go?
You do not rotate rotors. Replace a bad rotor or have it machined if possible. Never rotate them to another wheel location.
bad brake rotors or alignment shocks struts
bad rotors