Across:
   1. Artful fellow with a key to escape with her (6)
   5. Urbane heart-throb with latest in suave casual dress (8)
   9. Sweet innocent rube confused in debonair surrounds (8)
  10. Game professor taking on hollow history, creating division in kingdom with various classes (6)
  11,24dn. On Ginsberg, I get confused ... he was involved with Channel 9, Melbourne: "The Sex Pistols and The 17 4"?! (6 5)
  12. Led units in action and offended (8)
  13. Last of all to plead requested second chances (4)
  15. Furthermore, fellow coming back via country before 1992 (10)
  17,4dn. Outrageous tab, error betraying lucrative crime (5 5 7)
  20. Glossy cover removed to reveal something unfortunate (4)
  21. see 8 down
  23. Russia essentially caged bear, rattled (they are often rattled) (6)
  25. Guard southern gate? (6)
  26. Limited by their rig at encountering water (8)
  27. Doctor caught in money's corrupt condition (8)
  28. Message imprisonment sends everyone regarding society's leaders: they don't want to share their wealth! (6)
Down:
   2. During strip, he played piano chords, mixed with a bit of Eagles and Queen (9)
   3. Drug killing one's bird (5)
   4. see 17 across
   5. Much bike-sharing arranged in county of 17 4 (15)
   6. They manage keys to your public internet sites, to secure openings (7)
   7. Target of 17 4, Mr Neeson reclined or stood up? (5 4)
   8,21ac. 17 4 organiser, in Big Apple before check came back, sold out (5 8)
  14. Some decide Tang at Sizzler's turned and gone stale (9)
  16. Policeman's prices not flexible (9)
  18. Accomplice involved but briefly as target sighted (5-2)
  19. Most run off as a way to magically fix things (7)
  22. Lament ghastly glee preceding nasty finale (5)
  24. see 11 across