Hi Jon - I can't answer either of your questions properly, maybe someone else can. I have a 2004 automatic CLK 240, and it has COMAND.
However from driving manually on all my previous cars, your clutch symptom suggests plate wear. Master & slave cylinder problems usually show as pedal 'dip' - ie the pedal will sink to the floor under steady foot pressure as the fluid leaks past the seals. If your clutch pedal is not doing that, your cylinders are probably OK. Is there plenty of fluid in the reservoir?
COMAND features vary with the year of manufacture. My 2004 model cannot take DVDs or be modified to fit an iPod interface, I was told by local my M-B dealership. You might be lucky.
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