Across:
   1. see 26
   5. Use your ace perhaps (not your first) as something a 3 might bear (7)
   9. Hint for noses, 60% of which get quite loud (5)
  10. see 17dn
  11,20. Bill, in February '18, appeasing 3s and public impressions? (14 2 3 6 3)
  14. Initially, my idiotic fury gives illusion of relief (6)
  16. Least confident reinvest poorly (8)
  18. Loathed operation - primarily by which Tom boy "fixed" (8)
  19. Schoolboy agreement? (6)
  20. see 11
  24. New chairman's opposing authority (9)
  26,1. Tragic 3, ruined lady in movies (5 7)
  27. Heart, with energy, turned head before church (7)
  28. Stir set, Tortured Artists' subjects (7)
Down:
   1. Wave wand for new beginning (4)
   2. I cover most pieces as music producer (5)
   3. She demands a 2, and foolishly utters gaffe (11)
   4. New primates, those that sport dog collars (5)
   5. 4 running around new church as atonements (8)
   6,25. Some spinach salad tossed in waste receptacle (3 3)
   7. Exotic rare illness is killing less carriers at altitude (9)
   8. Blowing up mad dog in a tent (10)
  12. Notice vehicle has stick for forward motion (11)
  13. Soften and make speech after Earhart, aviation leader, lost (10)
  15. Counters of numbers that aren't complex butt in (9)
  17,10ac. Prominent 3... somehow impel us, the rank men! (8 9)
  21. Cougars such as wild 17 don't think men leer (5)
  22. Half mercifully organised the foul deed (5)
  23. These confirm a positive decision (4)
  25. see 6