Financial Times 12,576 by Cinephile

For the first time since I started blogging I had a clue that I could not solve! See 17 across. There are others that I do not completely understand and a couple that I think do not work well. Maybe I am missing something — I hope so — but on the whole I find this puzzle rather unsatisfactory. There are a few excellent clues though, notably 20A, 21D and 22D.

Across
1. SUBMIT – SUMMIT (top) with first M (master) changed to B (bachelor)
4. ABSTRACT – double definition
8, 10. ROCKET LAUNCHER – ROCKET (salad plant) + A (a) in LUNCHER (one having a meal)
12, 3. NEWS ITEM – NEW (fresh) + SITE (location) + M (mile)
13, 6. TOMBSTONE – TROMBONE (brass) with R removed and ST (saint) inserted
14, 18. KNOWLEDGE – K (king) + NOW (present) + LEDGE (shelf)
17. SILVER SCREEN – anagram of SILENCER+V+ERS (Queen’s). Someone gave me this answer (see Comments). I blocked myself on this clue because I had 1 down wrong.
20. BANQUOS GHOST – BANQ[uet] + OS (outstanding) + G (good) + HOST (person doing the honours)
25, 27. SHIPMATE – double definition of sorts
28. TENDENCY – TEND (look after) + ENCY[clopedia]
29. FAG END – GEN (information) in FAD (craze)
30. CUTPURSE – CURSE (utter oaths) with UTP or TPU inserted. But how does OUTPUT give us UTP or TPU?
31. MEDLEY – MED[iterranean] (sea) + LEY (field). LEY is a variant on the more common LEA.

Down
1. SERENEST – SERE (formerly dry) + NEST (home). I had a lot of trouble with this one because I wrote in the answer SERENITA — even though I could not see where NITA came from. Venice is known as La Serenita. But the English form makes more sense.
2. BACK WALL – BACK and WALL are elements of a desperate situation as in “back to the wall” and squash players play off a back wall. I found this quite difficult.
5. BLABBERMOUTH – LAB (party) in BB (Barbados) + [v]ERMOUTH (flavoured wine). BB is an ISO code for Barbados.
7. AT HAND – hidden word
8. THROWN – homophone (throne)
11. CONSEQUENCES – double definition
15, 23. PENALTIES – anagram of PALESTINE
18. BOTHWELL – double definition. Bothwell was Mary Queen of Scots’ second husband.
19. STUPIDLY – PUTS backwards (sets up) + IDLY (in vain)
21. STATIC – double definition. Good one.
22. RENNET – TENNER (money) backwards
26, 24. BEAU GESTE – anagram of A GUEST in BEE (busybody)