I'm struggling with left side, specifically NW corner, but thanks to syzygy for hints on 9A, which had floated in and out of my head at one point, but which I couldn't fit in, though the penny has now dropped.
Pendragon: I am the same when it comes to clues others find hard, and vice versa. I had 12D in fairly early, and you're right with the A at the intersection of 15A and 12D. It's one of the more unusual names, and a four-letter one. I can't see what else could work, in fact, with the other checking letters.
I think I have 7A, but the definition bit makes no sense to me!