Across:
   1. Cleans around last bits of graffiti, as scrawling horrifies (8)
   6. French philosopher turned to spice (5)
   9. Entrant returning in "Catching Fire", "Mockingjay" (5)
  10. Fix up concerning subprime disaster when penny dropped (9)
  11. Fashionable end of city engulfed in silent disaster (2 5)
  13. Taking it, a penny dropped: crazy drugs vital ingredients of rock and roll! (7)
  14. see 3 down
  16. Maximum bailouts securing maximum city? (6)
  19. see 27 down
  20,22. Mathematician, having sunk right into gambling, managed inverted irrational root to exchange for money (8 7)
  23. 20 22 found one in 27 19 primarily positing a 'regular' arrangement denying owning oneself, as represented by the less educated (7)
  25. Block part of access to new allotments (9)
  26. In vain, one trying problem? (5)
  28. Steer around problem requiring this perhaps (5)
  29. Oddly 27 on term, 27 lied about whats in a 27! (8)
Down:
   2. Master of 18 (among firsts arising)... might be indigo? (3)
   3,14ac. Master of 8 with creative spark, or vagary? (5 8)
   4. Professional who may get dumpy, level with decrepit voyeurs by end of year (8)
   5. Short musical bursts orchestra section not getting right (6)
   6. Crazy Rob's quite the familiar identity (9)
   7. It shows a degree of silliness going to ones head? (11)
   8. Aches & strains part of game (5)
   9. Pain in back possibly with extremes of effort in game (7)
  12. Not at all hard to punish sons: she arranged hangings (11)
  15. Not holding fast, get meaner deal (9)
  17. Kinda text hero, exposing each word within... she makes books more useful! (7)
  18. Master of 3 14 (among firsts arising)... might be indigo? (4 4)
  21. If you don't mind quiet lake, relax (6)
  22. Tread on it in flight? (5)
  24. Currency up in Greece regularly (5)
  27,19ac. Fixed idea in fundamental field of mathematics (3 6)