I thought this was hard. Got the theme from 8D.
Had to use the missing letters solver on this site for 27A and 24A (even though I have seen that device used before in the Everyman).
No way I would have got 17D without coming here and I thought it was a weak clue.
I read 7D as 2 3-letter words for "kind of funny" (as in nonsense) reversed but I also see the repeated definition as well thanks to a post earlier, maybe it was intended to be read both ways?
19A was my favourite clue since it was very topical after his performance the other week (which I did not see or hear, probably for the best that, but I saw everyone complaining/laughing about it on twitter.
A company I used to work for (now defunct) did a Playstation 2 game about one of the '7's more famous characters (not one of the answers in this crossword though). Was a feline wearing something large and distinctive.