Across:
   8. Smite fellow with crass movement, seizing University right (6 4)
   9. They established base for spies (4)
  10. Went on wild date with nurse (8)
  11. Among odd characters in thread, "Grinch" particularly sad (6)
  12,15. Twist mouth and sniff at player in 14 21 (6 7)
  14,21dn. How tidy combing made 17 good for three 4 22 (8 6)
  15. see 12
  17. Modern technology used in sheer entertainment (7)
  20. Secure clean building for summit (8)
  22. see 4 down
  24. They are said to weep with intent expression of pain (6)
  25. see 1 down
  27. Fear some walls have them? (4)
  28. Having taken the heat for too long, haywire Hoover hocked away the hospitals (10)
Down:
   1,25ac. Improve on awful scan, or film might get this (4 8)
   2. Climb like unit of currency (6)
   3. End craze, moving buffet (8)
   4,22ac. Recognition issues dogging institution (7 6)
   5. Scoring a "ten" is not for everyone (1-5)
   6. Slam diet developed for competitor near 20 (8)
   7. Put plainly, did he creep out? (10)
  13. Derivative grain oil UN developed (10)
  16. Competitor near 20 is in, flat out (8)
  18. Creating trouble, great leader turns to one fast (2 1 5)
  19. Notice piece in press: regimental leader having more pips (7)
  21. see 14 across
  23. Branch organiser, entertaining host (6)
  26. 2, 4, 5 and 8 competing in tournament (4)