Really nice! Lots of smooth anagrams and fun, misleading surfaces.

Across

1

Intriguing board game could be redesigned without bishop (6)
CLUEDO — anagram (redesigned) of COULD bE without b (bishop)

4

Film the writer with assorted barmen (8)
MEMBRANE — ME (the writer) anagram (assorted) of BARMEN

9

Fed a variety of ducks around edges of lake? (7)
SUCKLED — anagram (variety) of DUCKS around LE (outside letters of lake)

11

Harshly criticise farewell musical performance (7)
CANTATA — CAN (harshly criticise) TA TA (farewell)

12

Approve design adapted for snooping (13)
EAVESDROPPING — anagram (adapted) of APPROVE DESIGN

14

Water heater, plugged in, not about to activate (4,2)
TURN ON — URN (water heater) inside reversal (about) of NOT

15

A child star reflected in agreement (2,3,3)
AS ONE MAN — A SON (child) reflection (reflected) of NAME (star)

18

Massive loss absorbed by energy producer (8)
COLOSSAL — LOSS inside COAL (energy producer)

20

Principal is to join paper (6)
STAPLE — double def.

23

Open auction organised by me in the past (4,4,1,4)
ONCE UPON A TIME — anagram (organised) of OPEN AUCTION, ME

26

Saw ranger strangled by lead (7)
PROVERB — ROVER (ranger) inside PB (lead)

27

Old music-maker, dressed in blue, is formally recognised (7)
SALUTED — LUTE (old music-maker) inside SAD (blue)

28

Solicitors who may authorise and not sign (8)
NOTARIES — NOT ARIES (sign)

29

Head of the unusual adder may be sold (6)
TRADED — T (first letter of the) anagram (unusual) of ADDER

Down

1

Cooked cutlet comes without core salad ingredient (3,7)
COS LETTUCE — anagram (cooked) of CUTLET COmES (without middle letter)

2

Bunch with no limits completed show? (7)
UNCOVER — UNC (bunch without outside letters) OVER (completed)

3

False impressions and lies sound contrived (9)
DELUSIONS — anagram (contrived) of LIES SOUND

5

Dreamer is consumed by distortion of space and time (8)
ESCAPIST — IS inside anagram (distortion) of SPACE, T (time)

6

Members of club on dinkum Aussie beach (5)
BONDI — hidden in cluB ON DInkum

7

Union's group of doctors left game before the end (7)
AMALGAM — AMA (group of doctors) L (left) GAMe (without last letter)

8

Ingredients of cultured American cheese (4)
EDAM — hidden in culturED AMerican

10

Staff retired next to married quarters for boarders (4)
DORM — reversal (retired) of ROD (staff), M (married)

13

Euros invested in dodgy fund finished exposed (10)
UNDEFENDED — E (Euros) inside anagram (dodgy) of FUND, ENDED (finished)

16

NAB teller upset WA, for example (9)
NETBALLER — anagram (upset) of NAB TELLER

17

Compound of blue lava is precious (8)
VALUABLE — anagram (compound) of BLUE LAVA

19

Yahoo found in possession of ring and fine watch (7)
LOOKOUT — LOUT (yahoo) around O (ring) OK (fine)

21

Fashioned tine piercing seedcase is sharp (7)
POINTED — anagram (fashioned) of TINE inside POD (seedcase)

22

Catchers of prime suspects primarily? (4)
COPS — first letters of Catchers Of Prime Suspects, &lit

24

Head of company relocated here to provide encouragement (5)
CHEER — C (first letter of company) anagram (relocated) of HERE

25

European country quelling a revolution (4)
SPIN — SPaIN (European country) without a