Like others, found this one very difficult.
Please put me out of my misery with last two, where I think I have answers but cannot parse.
36D "Recruit exhausted -- good means of showing it?"(10). Answer seems to be "signalling", but why?!
14A "How the colours mix, dash it!" (4,9). Answer seems to be "race relations". How does it parse? "Dash" could be "race", but "it"?!