Across:
8 Juvenile (lad = LA-D-) paper’s (ID papers = -I-D-) lead: “Advice (lead ‘Advice’ = -A) (LA-DI-DA) can be pretentious, in a manner of speaking” (LA-DI-DA)
9 Following orders (OBEDIENT), old (O-) Oriental (East = -E-) imprisoned, sadly (= anagram indicator) in debt (in debt = -B-DIENT) (OBEDIENT),
10 A native supporter of Glasgow Celtic (SCOT) or ‘Buoys’ leaves boy scouts (‘Buoys’ leaves/from ‘boy scouts’ = octs = SCOT),
11 Piece (ARM-) on elderly (-AGED-) gangster (-DON) (ARMAGEDDON) leads to the ultimate conflict (ARMAGEDDON),
12 It’s a risky business (CASINO) for those overseeing student applications (Central Applications Office = CAO = CA-O) admitting error (-SIN-) (CASINO),
14 Those in Cairo (AFRICANS) out of order (= anagram indicator) in fracas (in fracas = AFRICANS),
15 Typical local jolly for old conductor taking time off (A BUSMAN’S HOLIDAY) with a (A) driver (BUSMAN-) from end of Christmas (end of ‘christmaS’ = -S) to Easter (HOLIDAY) (A BUSMAN’S HOLIDAY),
18 Cats (PERSIANS) in Spain (Spain = P-IANS) roaming (= anagram indicator) around summits of Estremadura, Rioja (summits of ‘Estremadura Rioja’ = -ER-) and far side of Pyrenees (far side of ‘PyreneeS’ = -S-) (PERSIANS),
20 Puts right (EMENDS) by sending me (me = EM-) back to finish (-END-) school (-S) (EMENDS),
22 Sick and tired (CHEESED OFF) of what’s said to the photographers (CHEESE-) and director (-D) not getting on (getting OFF) (CHEESED OFF),
24 Accommodation (FLAT) concealed by rising (= reverse indicator) coastal fog (concealed by ‘coasTAL Fog’ = talf = FLAT),
25 Obstruction (BLOCKAGE) case (case = B-AG-) involving rugby player from the scrum (-LOCK-) and second centre (second ‘cEntre’ = -E) (BLOCKAGE),
26 Levitations from reality television (‘Levitations’ from ‘reality television’ = ryelei = EERILY), in a spooky way (EERILY).
Down:
1 It’s a dash in the car (dashboard in car = FASCIA board) for spies (-CIA) following (= positional indicator) Swift (fast) briefly (‘fast’ without ‘t’ = FAS-) (FASCIA),
2 The clue (HINT) to why there are no wagons in Washington (no ‘wagons’ in ‘Washington’ = hint = HINT),
3 Legendary lover (CASANOVA) of Jonas (Jonas) loses the head (j) (‘Jonas’ without ‘j’ = onas), falling over (= reverse indicator) (onas = -SANO-) consumed by sparkling wine (cava = CA-VA) (CASANOVA),
4 Mexican hyssop raised (= reverse indicator) on the borders (‘MExican hyssOP’ raised on the borders = meop = POEM) in Limerick (POEM),
5 Combination (MERGER) of some summer geraniums (some ‘sumMER GERaniums’ = MERGER),
6 Bitter (VINDICTIVE) French wine (French ‘wine’ = VIN-) from back of beyond (back of ‘beyonD’ = -D-) put on ice (ice = -IC-E) splits natives from The Centre (‘naTIVes’ from the centre = -TIV-) (VINDICTIVE),
7 What definitely affects the retirement plan (INSOMNIA) will keep you awake at night (INSOMNIA),
13 Big demand (INSISTENCE) by member of the medical profession (sister) endlessly (r) (‘sister’ without ‘r’ = -SISTE-) found in public house (inn = IN-N-) with Clare (-CE) (INSISTENCE),
14 Fools (ASSES) in exercises sabotaged (in ‘exerciSES SAbotaged’ = sessa) Rising (= reverse indicator) (sessa = ASSES),
16 Dance (ball = B- -ALL) welcomes jazz (= anagram indicator) here (here = -EER H-) (BEER HALL) in Munich drinking establishment (BEER HALL),
17 Make foie gras, for instance (OVERFEED), with Dover (Dover) ingredients (= anagram indicator) (Dover = OVER-D) covering commission (-FEE-) (OVERFEED),
19 Level-headed (sane = -ENAS) artist (RA = AR-) retires (= reverse indicator) (ARENAS) in a number of stages perhaps (ARENAS),
21 Getting turn out of round table (getting ‘turn’ out of ‘round table’ = odable = DOABLE) is possible (DOABLE),
23 Impartial (OPEN) to the extremes of opium den (the extremes of ‘OPium dEN’ = OPEN),
24 The bank’s financial centre (banks ‘FInancial centRE’ = FIRE) sets off alarm bells (FIRE).