Across:
   1. Little comments like "that time of the month" to be wary of (6)
   5,26dn. 30 piece discovery of legendary submariner, originally fine in mind, gone crazy (7 4)
  10. Weird, swapping royal for new royal (5)
  11. 30 piece history of Y2K perhaps fuels a big mess (1 3'1 4)
  12. Slander senator, maintaining he wrote "The 15 10" (8)
  13. Dog ran off to get lizard (6)
  15. Winter fall of beaten towns, out of time (4)
  16. Experience defeat within, forced out and wound up (10)
  19. Poorly paid position in chaotic hipster inn (10)
  20. see 28
  23. 30 piece based loosely on "The 15 10" adapted for Buddhist school (6)
  25. 30 piece flier with neat prep work (5 3)
  27. Rebellious head of development is with team, not on vacation (9)
  28,20. 30 piece thief can, with rebel leader, get in back door (5 4)
  29. Tile got broken, hit from 23 (3 2 2)
  30. Film maker excited N.Y. side (6)
Down:
   2. It helps you get over the drink quickly, and somehow beats dope (9)
   3. Morrison finally accepted by his band as they are charitable (6)
   4. Tease south about where some laws are made (10)
   5. Five cut back? (4)
   6. Main elements of air oddly so turbid, less air comes through these gaps (8)
   7. Dicing with death, initially missing topping (5)
   8. Reneged on arrangement, changed to appease environmentalists (7)
   9. Peers squeal, excited (6)
  14. Concerning, calamitous medical scan... emergency department given new task (10)
  17. Sane surrounds in which insane Pop can be held (9)
  18. Go, before dubious expertise found wanting! (8)
  19. One not believing in ridiculous field? (7)
  21. Terribly indignant after soldier perhaps left taking food (6)
  22. Enrages organisation, forgetting one's artistic pigeonholes (6)
  24. Notes unfortunate beginning (5)
  26. see 5 across