Across:
8 Revenue (Revenue on Line = ROS), turnover (= reverse indicator) (ROS = SOR-) and bank (bank/tier = -ROW) (SORROW) distress (SORROW),
9 The Centaur (HORSEMAN) from Mount (mount = HORSE-) Mainalo initially (‘Mainalo’ initially = M-) and Nafplion summits (‘And Nafplion’ summits = -AN) (HORSEMAN),
10 Tag along without a lot (‘tag along’ without ‘a lot’ = agng = GANG) of The Mob (GANG),
11 Former (EX-) writer (-PEN-) and director (-D-) up to the job (-ABLE) (EXPENDABLE), producing Throwaway (EXPENDABLE),
12 Don’t hesitate to buy into (SNAP UP) what Venus flytrap will do for you (SNAP UP),
14 Group of shops (CH-AIN) around a (-A-) place (-PL-) (CHAPLAIN) keeping the faith in the units (army CHAPLAIN),
15 Walk across the road (PELICAN CROSSING) to bird (PELICAN) at Checkpoint Charlie (CROSSING) (PELICAN CROSSING),
18 Seth (Seth = -EST H-) cracking up (= anagram indicator) in Italian city (R-OME) (REST HOME) looking after the old folks (REST HOME),
20 The way (SYSTEM) to close cases (close ‘caseS’ = S-) for The Yard (-Y-) with links to The Branch (-STEM) (SYSTEM),
22 Night-watchman (ASTRONOMER) spends a lot of time looking into space (ASTRONOMER),
24 Settled account (PAID) with charity (-AID) after (= position indicator) pressure (P-) (PAID),
25 Doses, etc., (doses etc) doctored (= anagram indicator) (doses etc = COSSETED) and spoiled (COSSETED),
26 Calling (CAREER) mercenaries letting off mines (‘mercenaries’ letting off ‘mines’ = ercare = CAREER).
Down:
1 theterritory (the territory /estate = DOMAIN) .ie, for one? (ie. = Irish domain = DOMAIN),
2 Local Yank (yank/pull = DRAG) taken in by Ava Gardener (taken in by ‘ava GARDener’ = gard) going all way back (= reverse indicator) (gard = DRAG),
3 Small (S-) tiny (tiny/wee = -WEE-) port (-P-) consumed in brew (tea = -T -EA) (SWEET PEA) produced in the garden (SWEET PEA),
4 Boutique (SHOP) for posh (posh) dress (= anagram indicator) (posh = SHOP),
5 Take film away from unfamiliar (take ‘film’ away from ‘unfamiliar’ = unaiar = URANIA) muse (URANIA is Muse of astronomy),
6 The best three (MEDALLISTS) tips at sea (tips at sea = -LISTS) going after (= position indicator) Scott, for one (Scott MEDAL-) (MEDALLISTS),
7 Mark (mark/symbol = SIGN) Bellow (CALL) from the start (= positional indicator) (CALL SIGN) produces ID for radio station (CALL SIGN),
13 Distress (PAIN-) from infectious disease? (-TB-) Take speed (-RUSH) (PAINTBRUSH) – the type Monet used in his atelier! (PAINTBRUSH),
14 Seasonal work (CYCLE) for the pedlars (pedlars) in a manner of speaking (= homophone indicator) (for the ‘pedlars’ = for the ‘pedallers’ = CYCLE),
16 One miser (one miser) out of sorts (= anagram indicator) (one miser = EMERSION) in the process of coming out (EMERSION),
17 Caught (-C-) among wild (= anagram indicator) turbots (turbots = OBSTRU-T) (OBSTRUCT) found in hamper (OBSTRUCT),
19 Fancy (ORNATE) scam from Sacramento (‘scam’ from ‘sacramento’ = raento = ORNATE),
21 Cut some lines (EDITED) reflecting (= reverse indicator) a concern for The Seafarer (tide = EDIT-) by Ezra Pound around the edges (‘Ezra pounD’ around the edges = -ED) (EDITED),
23 Produced (MADE) the extremes of the Marquis de Sade (the extremes of the ‘MArquis de saDE = MADE),
24 In America, use a lot (use a parking lot = PARK a car) in Phoenix, for example? (Phoenix PARK).