It took me 2.5 days of penetrating oil and 3 - 4 hours of sledge hammer'n on my 1995 E320 to brake my right front rotor loose, the thing had rusted on. I finally resorted to prying the rotor loose with a prybar braced against the ball joint.
My left came off after 20 minutes of easy swats with the sledge. Don't worry about damaging the rotors coming off, your only going to be throwing them away.
As for hanging the calipers, just replace your hoses and you don't have to worry about letting them hang loose.
After all that, and a good brake fluid flush, my ride was better than ever.
P.S. I went with the 'grooved' rotors, and I am not sure I can tell the difference. They are meant to remove the gases generated by the pads faster. Can't say for sure they stop the car any better, but they look cool.