I had a similar experience several years back with the back brakes on my 240D. They were glowing red hot. I cracked open the line for the rear brakes at the base of the master cylinder, it released pressure and I drove it a zillion miles 'til brake time without ever having any further problem like this.

The problem was either the master cylinder or possibly the proportioning valve. You replaced the master cylinder and I think that cured the problem.

The warmth of the rotor could be just new pads that are wearing in. I would ensure that the entire system is flushed with fresh fluid and see what happens. You may very well have it fixed now.

Best of luck,