Across:
8 Trim (h) crisp (fresh) ('fresh' without 'h' = FRES-) company (-CO) (FRESCO) painted by muralist? (FRESCO),
9 Retire (WITHDRAW) from Takeaway (WITHDRAW),
10 Good-for-nothing (LAZY) non-professional (lay = LA-Y) outside zone (-Z-) (LAZY),
11 Relishes (CONDIMENTS) chewing (= anagram indicator) second mint (second mint = CONDIMENTS),
12 Give out to (ASSIGN) young woman (lass) losing the head (l) (‘lass’ without ‘l’ = ASS-) up (= reverse indicator) north (NI = -I-N) around summit of Gullion (summit of ‘Gullion’ = -G-) (ASSIGN),
14 Lets her (lets her) off (= anagram indicator) (lets her = SHELTER-) to open secure (open letter of ‘Secure’ = -S) (SHELTERS) safe houses (SHELTERS),
15 Cleared all the balls in one visit to snooker table (MADE A CLEAN BREAK) and walked out for good (MADE A CLEAN BREAK),
18 Sounds like (= homophone indicator) Cologne (“scent” = “sent” = SENT-) is popular (-IN-) with the foreign (‘the’ foreign = -EL) (SENTINEL) guard (SENTINEL),
20 Bug (INSECT) trendy (IN-) splinter group (-SECT) (INSECT),
22 Got stick, for instance (-FETCHED), after (= position indicator) meal (fare) isn’t finished (e) (‘fare’ without ‘e’ = FAR-) (FAR-FETCHED) – it’s presumably hard to swallow! (FAR-FETCHED),
24 Rally (MEET) those on the periphery around (= reverse indicator) Texas Hold ’Em (those on the periphery ‘TExas hold EM’ = teem = MEET)
25 It’s concerning (RE-) having to wait on (to wait on = -SERVE-) endless (end ‘lesS’ = -S) (RESERVES) books (RESERVES),
26 Broadens one’s knowledge, for instance (WIDENS), with (with) a fair amount of (half of) (half of ‘WIth’ = WI-) study (-DEN-) that’s top secret (top ‘Secret’ = -S) (WIDENS).
Down:
1 Snaps (BREAKS) with those characters at the end of 15 across (end of 'made a clean break' = BREAK-) on bender (-S bend) (BREAKS),
2 Spot (ESPY) prize ultimately (‘prizE’ ultimately = E-) for a gent? (‘a gent’ = ‘agent’ = -SPY) (ESPY),
3 One of those on the radio (volume button = VOL-) with headphones (cans) briefly (s) (‘cans’ without ‘s’ = -CAN-) in charge (In Charge = -IC) (VOLCANIC) of one of those likely to blow top (VOLCANIC),
4 Pen (female swan = SWAN) concealed by Miss Wannamaker (concealed by ‘misS WANnamaker’ = SWAN),
5 Raise a stink not using Asian (‘raise a stink’ not using ‘Asian’ = restik = STRIKE) batter (STRIKE),
6 Relative (Da) sets-up (= reversal indicator) (Da = AD-) speculative enterprises (-ENTURES) (ADVENTURES) for those looking for escapism (ADVENTURES),
7 Turns up (= reversal indicator) broadcast (air = -RIA), etc., (etc = -CTE-) on an old boat (able-bodied seaman = ab = BA-) (BACTERIA) with bugs (BACTERIA),
13 Recognised (IDENTIFIED) one (I-) gets good books (New Testament = -NT-) at film institute? (Irish Film Institute = -IFI-) Indeed! (‘NT’ + ‘IFI’ in the letters ‘deed’ = -DE-ED) (IDENTIFIED),
14 Rob (steal) told (= homophone indicator) (‘steal’ = ‘STEEL’) it’s very tough in construction (STEEL),
16 Statistical norms (AVERAGES) over (= reverse indicator), for example (e.g. = -GE-), in South Africa (SA = -A-S) associated with father (Rev = -VER-) from authority (A-) (AVERAGES),
17 Establish beyond dispute (NAIL DOWN) spike (NAIL) is in Ulster (DOWN) (NAIL DOWN),
19 Vegetarian removes gear (‘vegetarian’ removes ‘gear’ = vetian = NATIVE) in the local (NATIVE),
21 Does homework (CLEANS) in the middle of 15 across (middle of ‘made a CLEAN break’ = CLEAN-) before (= positional indicator) school (-S) (CLEANS),
23 Is this the type of money offered to shut up (HUSH money) royal (His Highness = H-H) taking in America? (-US-) (HUSH),
24 Built (MADE) opening for 15 across (opening of ‘made a clean break’ = MADE).