Across:
1 Comedian (GAS MAN) has a job reading things in other people’s homes (GASMAN),
4 Various types (ASSORTED) initially at (initially ‘at’ = A-) the heart of Essex (the heart of ‘Essex’ = -S-) and rocky (= anagram indicator) Dorset (Dorset = -SORTED) (ASSORTED),
9 Coached (TAUGHT) for tense (tense = “taut” = “TAUGHT”) speech (= homophone indicator),
10 Adaptation (= anagram indicator) so on time (so on time = EMOTIONS) of Love/Hate (EMOTIONS),
12 Hurt (W-OUND) over hip (-HIP-) replacement for top (‘replacement’ for top = -R-) (WHIP-ROUND) fundraiser (WHIP-ROUND),
13 Drains coming out of residential (‘drains’ coming out of ‘residential’ = eietl = ELITE) establishment (establishment/high society = ELITE),
14 Rocky (= anagram indicator) Tuohy (Tuohy = YOUTH) has places to stay (hotels = HO-TELS) around the heart of Essex (the heart of ‘Essex’ = -S-) (YOUTHHOSTELS) where The Young Tourists are given residencies (YOUTH HOSTELS),
18 They arrive for the job (job APPLICATIONS) and are put to work in the computer department (APPLICATIONS),
21 Most of those in 27 across (‘horses’ = HORSE) could be found in 6 down, of course (HORSE could be found ‘on the flat’ of course / racecourse),
22 Slant (VIEWPOINT) of The Stand? (the stand = VIEWPOINT),
24 Mad plot (mad plot = D-PLOMAT) organised (= anagram indicator) around one (-I-) (DIPLOMAT) running a mission (DIPLOMAT),
25 Where you’ll find 27 across (find ‘horses’ on race COURSE / track) might be attractive to the swingers (is attractive to the swingers on golf COURSE),
26 Informers (rats = STAR-) upset (= reversal indicator) by those from school (-FISH) (STARFISH) lying on the beach (STARFISH),
27 Outlets (HO-SES) welcoming writing (from the 3Rs = -R-) (HORSES) by nags (HORSES).
Down:
1 Gate (gate = GETA-) production (= anagram indicator) goes on the road (on the road = -WAY-) for school (-S) (GETAWAYS) holidays (GETAWAYS),
2 Spike (SPUR-) with debts (IOUs = -IOUS) (SPURIOUS) is not genuine (SPURIOUS),
3 Regard with disgust (ABHOR) how Tom leaves bathroom (‘Tom’ leaves ‘bathroom’ = bahro = ABHOR),
5 Fair amount of (half of) seminary (half of ‘seminary’ = SEMI -) is cut-off (-DETACHED) (SEMI-DETACHED) from those sharing with the neighbours (SEMI-DETACHED),
6 Reviews (= reversal indicator) No (no = ON) Offence (theft = THE F-T) catching two figures central to villainy (two figures central to ‘villainy’ = -LA-) (ON THE FLAT) where jumpy gamblers, of course, are never to be seen (ON THE FLAT),
7 Cheated (TOOK IN) family (kin = -K IN), moreover (TOO-), from the start (= positional indicator) (TOOK IN),
8 Opens 17 down (opens ‘ash trees’ = -ASH-) in Germany (German domain = de. = D-E-), gets to finish order (finish ‘order’ = -R) (DASHER), and is quick out of the blocks (DASHER),
11 Old Eastern Europeans (YUGOSLAVIANS) broke up a few years ago and no longer living together (YUGOSLAVIANS),
15 Optimism (hope = HOP-E-) around park (-P-) is wide of the mark (OFF) leading to denunciation (leading to ‘denunciation’ = -D) (HOPPED OFF) to how Skippy got away (how Skippy, the bush kangaroo, got away = HOPPED OFF),
16 Pardon is (pardon is = PONIARDS) useless (= anagram indicator) for those involved in knife crime (PONIARDS/ short knives/short daggers),
17 Residue from the fire (ASH) in the forest (TREES) (ASH TREES) produces a raw material essential to the hurley industry (ASH TREES used for making hurleys),
19 Casts a shadow over (SHADES) Dante’s ending (‘Dantes’ ending = S-) in The Inferno (-HADES) (SHADES),
20 Foreign spirit (GRAPPA) doctor (G-P -) outside Knock (knock = -RAP-) is anonymous (-A) (GRAPPA),
23 Osteopath loses seat (‘osteopath’ loses ‘seat’ = otoph = PHOTO) and it’s captured for posterity by the cameraman (PHOTO).