Across:
8 Dubious (= anagram indicator) tablet (tablet = BATTLE) competition (BATTLE),
9 Sells bass (FISH SHOP) for the school group (FISH) society (S-) dance (-HOP) (FISH SHOP),
10 Drop a line (FISH) to half of those in 9 across (‘fish shop’ = FISH),
11 A mere squad (a mere squad = MASQUERADE) playing (= anagram indicator) with ball (MASQUERADE / masked ball),
12 Sleep (NAP-) with gangster (Al Capone = -AL-) and Frenchman? (Monsieur = -M) (NAPALM) That’s bound to be incendiary stuff! (NAPALM),
14 Minister (PREACHER) with power (P-) to get through to (-REACH) one of those in hospital (-ER) (PREACHER),
15 Takeaway (FISH AND CHIP SHOP) all of 9 across (‘fish shop’ = FISH SHOP) including group (band) with no leader (b) (‘band’ without ‘b’ = AND) for Nick (nick/cut = CHIP) (FISH AND CHIP SHOP),
18 Loathing (AVERSION) of American (A-) rendition (-VERSION) (AVERSION),
20 Show off (= anagram indicator) suites (suites = TISSUE) in The Paper (TISSUE paper),
22 Audience (ATTENDANCE) from The Gate (ATTENDANCE),
24 Note (music note C-) in Vogue (-HIP) (CHIP) held by gambler (CHIP),
25 You could get that in 15 across (get SNACK BOX in ‘fish and chip shop’) in the biscuit tin perhaps (SNACK BOX),
26 The Star-Spangled Banner (US national ANTHEM) is obviously a type of country music? (ANTHEM).
Down:
1 Short (g) dance (‘jig’ without ‘g’= -JI-) in Greece (‘Greece’ = ‘grease’ = fat = FA-T-) sounds (= homophone indicator) initially attractive (initially ‘attractive’ = -A) (FAJITA) to dishy Mexican type (FAJITA),
2 The (the = ET-H) problem (= anagram indicator) involving college (-C-) (ETCH) – it might leave the wrong impression? (ETCH),
3 Course director (HELMSMAN) for pilot? (HELMSMAN),
4 Listener leaves in self-interest (‘listener’ leaves in ‘self-interest’ = efst = EFTS) with the newts (EFTS),
5 Take for granted (ASSUME) part of the overseas sum earned (part of ‘overseas sum earned’ = ASSUME),
6 Leaves out in the cold (OSTRACISES), as presenter (host) needing no introduction (h) (‘host’ without ‘h’ = OST-) is (-IS-) involved in track events for cars (races = -RAC-ES) (OSTRACISES),
7 Into the bargain (TOO-), lost (= anagram indicator) dole (dole = -DLE-O-) at job centre? (‘job’ centre = -O) (TOODLE-OO) That’s some parting shot! (TOODLE-OO),
13 It’s certainly disgusting (ABHORRENCE) getting make-up (= anagram indicator) on her brace (on her brace = ABHORRENCE),
14 Nutty type (PECAN) of writer (PE-N) takes in most of (p) Cork (‘cap’ without ‘p’ = -CA-) (PECAN),
16 Getting a call from the host (INVITING) is attractive (INVITING),
17 Stumbling block (IN THE WAY) to a Whitney (a Whitney = IN THE WAY) melody (= anagram indicator),
19 Behind (IN DEBT) those who owe Bill (IN DEBT),
21 Uninhibited extremes (‘uninhibited’ extremes = UNITED) one associates with being integrated (UNITED),
23 What the doctor said (NEXT) of noises coming out of extensions (‘noises’ coming out of ‘extensions’ = extn = NEXT),
24 Chocolate box (CUTE) for Ron taken off counter (‘Ron’ taken off ‘counter’ = cute = CUTE).