16d. In suggesting the Queen must go down, I cross the line (9)
I have INFRINGER which gives me RING inside INFER, but I'm not at all sure that it's correct.
This is also assuming I have 29a. correct.
29a. Colourful children's writer's fish-catching trick (6). I have CRAYON. CON outside RAY, but again I may be barking up the wrong tree, or fishing in the wrong pool!
Please put me out of my misery so that I can go and do something useful.