Thanks for the above guidance re 10. I got 33 during insomnia last night and an early morning consultation with Chambers gave me a word I'd never heard before. I'd welcome guidance as to the line to follow re 46 as its driving me and my partner nuts.
The answer to 19 is within Hamlet's speech on the arrival of the players. Tr(o)y reading it.
22 starts with the theme letter followed by a word Chambers (C) defines as 'a recess cut into a printing plate' giving a word C defines as a 'write-off'.
You might have a knees up once you solve 34 then go outside if you have planking once you get 77 (quite a coincidence that entries have to be in by 30 November but don't laugh when reading the start of the clue).