Across:
8 Turns up (= reversal indicator) at the start of 13 down (start of ‘art student’ = art = TRA-) with one of the Big Cats (puma) scratching the head (p) (‘puma’ without ‘p’ = -UMA) (TRAUMA) in shock (TRAUMA),
9 Triggered (AWAKENED) a late get-together (a late get-together = a wake = AWAKE-) for Edward (-NED) (AWAKENED),
10 Those at The Bar (taps) reject (= reversal indicator) (taps = SPAT) petty argument (SPAT),
11 Parsley, Sage, Rosemary and Thyme (MIXED HERBS) arranged in a musical sense (MIXED) by woman (HER-) associated with extremes of bluegrass (extremes of ‘BluegrasS’ = -BS) (MIXED HERBS),
12 It’s nothing (O-) to do with writing (from the 3Rs = -R-) by Hitch (hitch = snag) reviewed (= reversal indicator) (snag = -GANS) (ORGANS) in a number of newspapers (ORGANS),
14 One of those with a pension (one with a pension/hotel = HOTELIER) from 14 down (‘hotel’ = HOTEL-) that’s (that is = i.e. = -IE-) never-ending (‘neveR’ ending = -R) (HOTELIER),
15 Studying (HITTING THE BOOKS) punching (HITTING) by most of them (most of ‘them’ = THE) in 24 across (‘book’ = BOOK-) taking head shots (head ‘Shots’ = -S) (HITTING THE BOOKS),
18 What the waiter is hoping for (tips) – rise (= reversal indicator) (tips = SPIT-), fuel (fuel), free (= anagram indicator) (fuel = -EFUL) (SPITEFUL) bitter? (SPITEFUL),
20 You’re unlikely to hear this praise if you’re late (EULOGY), as typically it accompanies a put down (EULOGY).
22 Caught (C-) out initially (‘Out’ initially = -O-) going with heartless (heartless/remove centre = ‘a’) young man (‘lad’ without ‘a’ = -LD-) to the country (TURKEY) (COLD TURKEY) for complete withdrawal (COLD TURKEY),
24 Nabokov dismisses The Van (‘Nabokov’ dismisses the ‘van’ = boko = BOOK) – the one written by the author (BOOK),
25 Gets the band back together (REUNITES) to see Turin? (see Turin) Tricky! (= anagram indicator) (see Turin = REUNITES),
26 Stir up (stir up) panic (= anagram indicator) (stir up = PURIST) – the traditional type that’s uncompromising (PURIST).
Down:
1 Shopkeeper (DRAPER), doctor (DR-) and mimic (-APE-) taking risks from the start (‘Risks from the start = -R) (DRAPER),
2 Track (HUNT) both sides of human development (both sides of ‘HUman developmeNT’ = HUNT),
3 Reflects (= reversal indicator) music (rap = PAR-) by lead singer (lead ‘Singer’ = -S-) covered by greedy (-ME-AN) (PARMESAN), cheesy type (PARMESAN),
4 Socialist (MARX) to spoil (MAR-) vote in General Election (-X) (MARX),
5 The Highwayman (BANDIT) Bar (BAN-) is for the students (Dublin Institute of Technology = -DIT) (BANDIT),
6 Perfect place to have breakfast (CEREAL BOWL) in Clare (CE-) with authentic (-REAL) dish (BOWL) (CEREAL BOWL),
7 Time off in the plantation perhaps (TEA BREAK) for the rest of the brewers (TEA BREAK),
13 Draws on lecturer’s advice (ART STUDENT) in the study of the master (ART STUDENT),
14 Swearing coming out of watering holes (‘swearing’ out of ‘watering holes’ = thole= HOTEL) and inns (HOTEL),
16 Goes here and there (-ROVES) after (= positional indicator) little devil (IMP-) (IMPROVES) gets back on his feet (IMPROVES),
17 It’s not our agent (ENEMY SPY) in Yemen (Yemen) going crazy (= anagram indicator) (Yemen = ENEMY) for notice (SPY) (ENEMY SPY),
19 100 (100 = Roman C) leaving university department (‘faCulty’ missing ‘c’ = FAULTY) can’t be right (FAULTY),
21 Get out of bed (-ROUSE) after (= positional indicator) midnight (mid ‘niGht’ = G-) (GROUSE) to complain (GROUSE),
23 Banks kicking up a fuss (banks ‘KIcking up a fuSS’ = KISS) with a light touch (KISS),
24 Served up (= reversal indicator) sample of brown rabbit (sample of ‘browN RABbit’ = nrab = BARN) for stockholder (BARN).