As this is a rather large Christmas puzzle with a handsome prize on offer, could we perhaps restrict ourselves to hints and nudges rather than answers, as we do for other such puzzles?
At least in the early days.
A good idea, jono - and one I'll follow now! I wasn't sure of the answer I gave and, equally importantly, I was typing on a bus so my post was as short as possible.
I still have a few themed entries to sort out, but I can't fit what I have to the last paragraph in the rubric.
So far I have some categories with only one-word answers, and some with a two-word answer.