I have had a similar problem once. My cruise stuck and I had to throw it into neutral and pull it off the road. I waited a few minutes and started it again. It immediately redlined so I shut it down again. I couldn't imagine what was wrong. Eventualy I reached down ad grabbed the gas pedal. It had stuck to the floor. It came up no problem and after that everything was fine. My mechanic said it was the linkage and he lubed it or something. Hasn't happened again. (This happened while accelerating (resume) on cruise). Haven't experienced the other problems.
Can't comment on the cold running or cold air problems.
PS I think you meant 2500rpm not 25,000rpm
1995 E420 - retired
1986 420SEL - retired