4  See 18 down

 9  15’s hen-party? (4)

10 Cape could be identical? (6,4)

11 Origins of Remembrances of Things Past, unfinished script edited by...?  (6)

12 Extreme security measures could be a spiritual afterthought (8)

13 Loose Women clue is distasteful  (9)

15 Sing out for 9? (4)

16 5 in distress, spun (4)

17 Mean quality of tinned fish-head? (9)

21 Eliot quietly laughs about potentially troublesome areas (8)

22 Often chips in flawed gesture (6)

24 Initially, Captain Ahab's temper is foul - possibly substance of Moby Dick?  (10)

25 Free love - a good deal? (4)

26 On average, one’s hiding after withdrawing weapon (6)

27 Grandpa's first delay, tottering like an old man (6)

 1  See 23 down

 2  Censor Trade Union language (5)

 3  24 without wave crashing on cold, hard lifestyle (7)

 5  Troublesome deity over city (6)

 6  Reformed scoundrel is returning on trip (9)

 7  Pinpoints in/out smash - feature of tennis shot, perhaps? (7)

 8  Proper artist tries out denizen of 18,4 (5,8)

14 Monitor eastern hail-storm beginning with rain (9)

16 Lie with painter (7)

18/4 Famous 10 way of drinking? (7,6)

19 Poet's Inferno found in reflection of Ulysses, conclusively?  (7)

20 Foremost of historians/outstanding poet (6)

23/1 8 dispensing random advice (5,7)