Probably the least of your worries would be exploding. I would be more concerned about that 'timing belt' going out since there is no Mercedes that doesn't use a 'chain' for that function.
On older MB's some A/C problems are due to the air exchange motors behind the dash being worn out and maybe not the 'system' at all. Turn on the A/C and drive around a while. Get out and look under the car. If water is dripping constantly from the center of the car, but the A/C isn't cooling well, then you may need the vacuum elements replaced. I replaced my compressor and a leaking hose only to find that my system was only pulling in outside air. As my tech put it "even the best A/C system can't do it's job breathing only 100 degree air!"