The warm restart stall is the nature of the beast. Get in the habit of poking the throttle just when it fires on a hot or warm restart, and it won't stall.

A bit of uneven idle roughness when the engilne is above 60C is also the nature of the beast because of the lean idle mixture. You might notice that it idles smoother below about 60C, which is the about the point where the engine goes into closed loop operation and maintains a stoichiometric (14.7:1) mixture under all operating conditions except WOT. Non-emission control engines idle at about 12.5:1, which is the point of best idle quality.

The Mercedes service literature states that lambda equipped M103s will not idle as smooth as non-lambda versions.

Duke