Gee, I must talk too much!
Several causes of warped rotors, but the leading one is probably very hard braking and then sitting at a complete stop, so the pads insulate the part of the rotor they cover.
Get those pads out of there, they are at least glazed. Groaning or squealing means aftermarket, rock hard pads, and they are probably the cause of your warped rotors -- too hard, glaze, then cause you to use too much braking effort, overheating them.
You need to driver VERY gently for several hundred miles on new pads. Try to avoid "panic" stops (hard enough here, let along in major traffic!), and make several firm stops from 35 mph with as much cooling time as you can between to wear the fur off the new pads after you put them in.
Definitely check the rear brakes. Rear rotors can warp, and if the parking brakes were dragging (from not releasing the parking brake) and then adjusted too tight, they can rumble, too. Won't get worse when braking, though.
A sticking piston can make the car groan at low pedal pressure stopped. Can also make the car jerk when coming to a complete stop with light pedal pressure.
On my Volvo, I think i have either a sticking piston/s up front, or air in one circuit that makes the pads vibrate. Not a rotor problem, as heavy pedal makes the noise and vibration go away.
If the rotors were run underthickness and the pads jammed on the antirattle spring, caliper rebuilds are in order. This is easy, the only really hard part is getting the piston back in at the correct rotation point -- impossible to move in the bore without the special tool.
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!