Although not presented in the traditional "jigsaw" format, this is an "alphabetic" puzzle, in the sense that there is exactly one answer starting with each letter of the alphabet. If you'd like the jigsaw version, it is here.

Across:
   7. Image of gunners beset by axes (1-3)
   9. Is it Maton? I suspect fakes! (10)
  10. Tablas were adapted for rock that erupted (6)
  11. Orderly presentation sent sane insane (8)
  12. Musician, 80, losing head, paranoid about being followed by nazis (5 4)
  13. Threads of inherited DNA segments reported (5)
  15,26. Ridiculous craze: rip flesh for famous chemist, 200 (7 6)
  17. Subject of reflection? (No reflection feels weird!) (7)
  20. Perhaps position me around Broken Bay (5)
  22. Traumatic war nigh? Or worse? (9)
  25. Challenging final "Dynasty" in which you dismatle their ploy finally? (8)
  26. see 15
  27. The garden, via Jerusalem, where Jesus nigh wept, where arresting ends up being...? (10)
  28. Join stinky core, turning (4)
Down:
   1. Amazing rake worked inside angle (8)
   2. I sort vice out, achieving triumphs (9)
   3. One going away is, to Nazi, wonderful? (7)
   4,19. Singer, 100, in vanguard, has had to travel while sparing pennies (5 7)
   5. Early entries admitted to Lords, a bit charged (8)
   6. Fun is only permitted all at once (6)
   8. Long chat about the end (5)
  14. English complain at physical training and education, but briefly, in code (9)
  16. Wondrous experiences, right before the ribs get broken! (8)
  18. Clothing that is bound to hang around? (8)
  19. see 4
  21. Entertained by Medusa fantasy (6)
  23. Wife getting his cocktail, which could cause a stir (5)
  24. Time, I wager, for mountain country (5)