Across:
1 It's not what you'd expect of high literature (LIGHT SENTENCE) and you'll have to do time for it, however little (LIGHT SENTENCE),
10 Smokier (smokier) mixture (= anagram indicator) (smokier = IRKSOME) is annoying (IRKSOME),
11 Messengers carried such medical symbols associated with staff (CADUCEI = the messenger gods carried herald’s wands/staff; also insignia of the medical profession), caught (C-) and arrested initially (‘Arrested’ initially = -A-) by Mussolini (-DUCE-), for one (-I) (CADUCEI),
12 Art from leather (‘art’ from ‘leather’ = lehe = HEEL) produced in part of Italy (HEEL),
13 Stay at The Centre (‘sTAy’ at the centre = TA-) on street (-ST-) close to bakery (close to ‘bakerY’ = -Y) (TASTY) – yum! (TASTY),
15 Elevated (= reversal indicator) part of the Taj Mahal building (part of the ‘taj maHAL Building’ = halb = BLAH) is as dull as dishwater (BLAH),
17 Tom Sawyer won’t take Metros (‘Tom Sawyer’ without ‘metros’ = awy = WAY), of course (WAY),
19 Local chap (fella) on the radio (= homophone indicator) (‘fella’ = ‘FELLAH’) with an Egyptian ploughman (FELLAH),
21 The smooth flowing manner (LEGATO) of architect on the fringes (‘ArchitecT’ on the fringes = -AT-) in the building game? (LEG-O) (LEGATO),
22 Druid (druid) production (= anagram indicator) (druid = RUDDI-) has direction (East = -E-) with writing (from 3Rs = -R) (RUDDIER) that’s even more colourful (RUDDIER),
23 Curl up (NESTLE) in front of (= positional indicator) the foreign (the = -LE) tree house (NEST-) (NESTLE),
25 Brief (INFORM) uplifting (= reverse indicator) address (Mr = -RM) by old (-O-) fogey heading (‘Fogey’ heading = -F-) to Ulster (NI = IN-) (INFORM),
27 Power-assisted steering (‘Power-Assisted Steering’ = PAS) – that’ll keep you on your toes (ballet step = PAS),
29 Fragment of multiple choice (fragment of ‘multiplE CHOice = ECHO) relates to what’s heard in The Cave again and again (ECHO),
30 Type of match (LIGHT) for all sides today (LIGHT on all sides of today’s grid),
31 Raising the devil on both sides (‘RAising the devIL’ on both sides = RAIL) of bar (RAIL),
34 Racier (racier) novel (= anagram indicator) (racier = ERRA-IC) set around time (-T-) (ERRATIC) that is unpredictable (ERRATIC),
35 What one of those types on The Wire won’t want to do (FALL OFF) in decline (FALL OFF),
36 Sounds like (= homophone indicator) Lewis (‘Lewis’ = ‘Luas’ = LIGHT RAILWAY-) is the first to school (first to ‘School’ = -S) (LIGHT RAILWAYS) with those taking routes on train tracks that aren’t heavy with traffic (LIGHT RAILWAYS).
Down:
2 Old writer used it for a dip (INKWELL) popular (IN-) on the weekend (on the 'weeK' end = -K-) approaching spring (-WELL) (INKWELL),
3 Bear (‘Pooh’ Bear) up (= reversal indicator) (Pooh = HOOP) in the band? (band/ring = HOOP),
4 Go back and forth (SEESAW) with energy (-E-) in choppy (= anagram indicator) seas (seas = SE-SA-) approaching start of winter (start of ‘Winter’ = -W) (SEESAW),
5 Holds the distinction (NICETY) of being taken in by Venice tycoon (held by ‘veNICE TYcoon’ = NICETY),
6 Objectives (ENDS) of Leonidas I utilising every other letter (every other letter = ‘lEoNiDaS = ends = ENDS),
7 Empty (a) bus (coach) (‘coAch’ without ‘a’ = COCH-) on meadow (-LEA) (COCHLEA) for part of The Hearing (COCHLEA),
8 Prone to plagiarism? (LIGHT-FINGERED) Presumably, a journalist with a typewriter! (LIGHT-FINGERED),
9 My wife, for instance (LIGHT OF MY LIFE), in The Sun as I see it (LIGHT OF MY LIFE),
14 After (= position indicator) bad start (‘Bad’ start = -B-) on ocean-liner (SAND-), head barman (Attorney General = -AG) (SANDBAG) is doing a job in case the bank fails? (SANDBAG),
16 Headless (p) units of wisdom (pearls of wisdom) (‘pearls’ without ‘p’ = EARLS) from peers (peers = EARLS),
18 Transfer art out (‘transfer’ minus ‘art’ = nsfer = FERNS) to place in Wexford (FERNS),
20 It’s a shady type (HUE) of hot sauce when you don’t have tacos (‘hot sauce’ without ‘tacos’ = hue = HUE),
21 Garland (LEI) returns (= reverse indicator) to trio in Dixieland (trio in ‘dixIELand’ = iel = LEI),
24 School (S-) where, at The Centre (‘wHERe’ at the centre = -HER-) in Czech Republic (CZ = -C-Z-), leader of insurrection (leader of ‘Insurrection’ = -I) (SCHERZI) produces a number of lively movements (SCHERZI),
26 A cold Adriatic wind (Bora), the first coming off (b) (‘Bora’ without ‘b’ = ORA-) island (-TORY island) (ORATORY) is the talk of the eloquent speakers (ORATORY),
27 Penny (P-) cuts things rather fine (mincer), starting off (m) (‘mincer’ without ‘m’ = -INCER) (PINCER) for crab’s nipper (PINCER),
28 Close (shut) most of (t) (‘shut’ without ‘t’ = SHU-) the paper (Financial Times = -FT-) with one (-I) (SHUFTI) quick look (SHUFTI).
32 Impatient desire (ITCH) for Channel (channel/moat = ditch) to remove the Head (d) (‘ditch’ without ‘d’ = ITCH),
33 Huffed and puffed (BLEW) in depressed (blue) state (= homophone indicator) (‘blue’ = ‘BLEW’).