Hey, thanks for all these great replies!

Now then, a little feedback...LOL

I replaced the radiator with a new Behr unit and also replaced the auxiliary water pump at 178,394 miles (July, 2011 - the same time that I replaced all of the cooling system hoses). I have checked the auxiliary water pump for leaks and detected none. I have not inspected the radiator and its seams with a fine tooth comb, so to speak. I will do that.

Doing a pressure test had slipped my mind. That is a great idea! I will probably use a local M-B shop to have them do that.

I will say this: A few days ago, I scrupulously cleaned the area where the dried coolant was everywhere I found it, let the engine idle for about 20 minutes, and could not find a singular drip. This must of had to do with the fact that the cooling system was not fully pressurized. Correct?

Great observation about the pattern of the dried coolant being too dispersed for a drip to be originating at the rear of the engine. That is the benefit of other minds thinking about this!

As for running the air conditioning vis-a-vis condensation: I have not been using the air conditioning...