It's a waste of time posting clues from this crossword (Schadenfreude's Great Circles from CAM) without mentioning the preamble to the crossword. The 7-letter answer to 18 down (from which two letters are removed to make a 5-letter grid entry) does not begin with n.
But one thing that you did fail to mention is that one letter in the definition part of each of these clues may be incorrect (the preamble says that this happens in 7 of the clues in the crossword).
p.s. I've only just started this myself and want to give it a proper go first, so I might have the answers later.
Wilbo, I'm sorry my original reply annoyed you. I tend to assume that people solving tricky crosswords such as the ones Schadenfreude produces come to sites such as this looking for hints rather than answers on a plate. That was why I gave the information about the initial letter. At the same time, there are lots of very helpful solvers of less devious crosswords who frequent this site. It's a shame to send them off on a wild goose chase.
Jumbuck's reply was polite and hence my polite reply. Your response and subsequent reply were the epitomy of arrogance and give the impression that you must have a very large chip on your shoulder, probably borne out of failure . Yes I do prefer to stick with the 'lots of very helpful solvers' , who you appear to look down upon, as in life it is often useful to help one another along the way .... a sentiment that clearly is beneath your lofty contempt.