Is the concierge lounge accessed by use of your room key?
Yes Can you get photos of the lounge?
They didn't allow it - privacy of the guests and all that.
What about the private concierge sun deck? Is that also accessed via room key?
Yes. What does that look like and are kids allowed up there?
It's the central portion of the deck 13 forward sun deck. They use frosted glass partitions to separate it from the rest of the deck area. It's a basic sun deck, but with very nice, cushioned wicker loungers and other furniture. I'm sure (concierge) kids are allowed there. Disney is the network of Suite Life on Deck, after all. 
Seriously, the "public" areas of that deck 13 area are divided into family and adults-only areas, but I saw no signs suggesting the concierge deck was adults-only. I tried to take some photos through the glass. We'll see if that worked out.