Make sure you save some (past the ~3 week point after bottling) for several months. The flavors will all mellow out and will be incredibly drinkable. Unless, you know, you like the harsh whiskey flavor :)
I made a Berliner with White Labs lacto and it fermented out like this as well. A frothy krausen formed and a nasty smell came from it. Beer came out delicious :D
I had the same issue. Sorry if someone already adequately responded. There is a blockage in the reg on the side where the pressure is creeping. pull off the hose, crank the pressure up, give a few puffs of air, and then reconnect.
There is a thread on cleaning your yeast. Most likely there is a lot of proteins and hop bits mixed in with the yeast.
Edit: https://www.homebrewtalk.com/f163/yeast-washing-illustrated-41768/
Get a fan inside of the keggerator to help move the air around. It sounds like your coils are getting ridiculously cold, and the cold air is primarily just sitting at the bottom?
If you haven't already put the raspberries in, I would wait at least 6 months before you add them. Any flavor from the fruits will be gone by the time the beer is ready if you add them now