Leaking issues in my 200 4R - any gurus available?

Front corner of the pan is going to be KD cable seal, filler tube or pan gasket.
Venting comes out the bottom of the housing (especially after you stop) because it runs off the interior of the bell housing and make a fair puddle where you park.

Now if there is a problem with the filter causing foaming it could burp out the vent, but still straight off the bottom of the housing and mostly after a stop and park.

I'll bet you 5 bucks it one of the three already mentioned (Pan, filler, KD)
A slight possibility of the servo cover Oring.