I think I have now solved 1ac, 3dn and 14ac, i.e the top left hand corner and I presume that 45 ac is the name of a hot wind whose last four letters are the name of the founder of a cult, but I am still no nearer to the theme. "Maltby" appears twice in the puzzle. I wonder if that is something to do with it?
Kepi is anagr of pike=peak. Have filled grid apart from 40 & 43. 40 could be Foot as FT is often paper. Wonder about nox then but no idea why. Just guessing. Got the missing o's but brain turns to jelly then.