2002 would be W203 which the quality is so-so (tilting towards bad) for Mercs.

Mercedes are known to have a lot of silly problems when they get older that is true. Search the forum with "W203" and "W202" will show you a majority of the problems faced by these 2 gens of C classes. It doesn't really matter if it's a sedan or a coupe the underpinnings are largely the same.

forced induction engines have a specific way of getting it taken care of - you should never shut the engine off after "spirited" driving where you reach high rpm causing high boost and high output because the internals of the supercharger would appreciate if you give it some time to cool down before you stop the fluid flow that goes into it (coolant and oil) and the supercharger should be fine. The engine is designed to go with the supercharger so the engine itself should not be a factor.

RWD can be really iffy in snow, but fortunately a 2003 Mercedes would have ASR and that will help you out in accelerating moments, as well as keeping your rear end from sliding into curbs and other blunt objects. Stopping is the same for any car with any wheel drive. ABS is standard so it stops very standardly (is that a word?)

but ASR is just some electronic gimmick you can get yourself out of light snow but don't expect the equivalent of a 4WD or 4 Matic from the ASR and TRC stability system.