I must say that, before I actually started this puzzle, I was a little daunted by the idea of as many as 14 unclueds, once I started I realised that for every Waring there would be a Gillow, then it all fell into place reasonably quickly, although for one unclued which could have been Lennon, I spent a wee while looking in vain for McCartney!
I agree with what I think is emerging as the consensus for 7a, namely that the first two words are the def