I just replaced the e-brake pads on my '84 190e. In my oppinion id say its a bad idea to remove the pads and go for a drive, the cam mechanism that expands the pads when the cable is pulled is only held together by a small pivot pin and on my car, in the process of replacing the pads this pin worked its way out of the assembly and fell off, there is very little room to work between the wheel mounting flange and the hub/ brake sheild. It took me about 20 minutes just to get things lined up and the pin back inplace. driving the car without the pads coudl lose the pin forever and I dont think the dealers have this pin on its own, youll probably need an entire sub assembly. you could try taping over the pin to hold it in if you really want to remove the pads and drive it as a test. also reassembling the ebrake assembly was tricky, especially installig the pad return springs, I dont have a brake spring tool so this made things harder using only a pair of needle nose pliers to pull the springs into position.
Hope this helps