Across:
8 She leaves osteopath (“she” leaves “osteopath” = otopat = POTATO) for Spud (POTATO),
9 Plagiarist (IMITATOR) is not capable of anything original (IMITATOR),
10 Gradually disappear (FADE), as one of the swingers might want to do this (FADE in golf),
11 Dean Hunter (Dean Hunter = UNDERNEATH) is out of place (= anagram indicator) below (UNDERNEATH),
12 Piece of countryside greenbelt (piece of “countryside greenbelt” = DEGREE) comes with a qualification (DEGREE),
14 What Jack stole from giant (Jack from Jack and the Beanstalk stole MONEYBAG of gold coins) bogeyman (bogeyman = MONEYBAG) somehow (= anagram indicator),
15 Sign (PRIVATE PROPERTY) of fighting in the conflict (army PRIVATE) on estate (PROPERTY) (PRIVATE PROPERTY),
18 Has a job (EMPLOYEE) to use (EMPLOY-) lots of drugs (E+E = -EE) (EMPLOYEE),
20 Extract (EXTORT) found in Tex-Mex tortellini (“Tex-Mex tortellini” = EXTORT),
22 Working on the film (EDITING) is not fashionable (OUT) (EDITING OUT) for those working with paper (EDITING OUT),
24 Wealthy (RICH) section of Maastricht (section of “Maastricht” = RICH),
25 A rose tub (a rose tub = SABOTEUR) designed (= anagram indicator) by one of those who put monkey wrench in works (SABOTEUR),
26 Hang on (REMAIN) – does this lot really want to stay in Europe? (REMAIN side of Brexit campaign).
Down:
1 Lay one’s hand on (LOCATE) what’s similar to 4 down (similar to “find” = LOCATE),
2 Expose (BARE) Max leaving bar exam (“Max” leaving “bar exam” = bare = BARE),
3 College (D-CU-) houses old (-O-) workers (-MEN-) with tonne (-T) (DOCUMENT) of paper (DOCUMENT),
4 Get hold of (FIND) bank’s final dividend (banks/sides “final dividend” = FIND),
5 Spill (= anagram indicator) tonic (tonic = CIT-ON) over recipe (-R-) (CITRON) for making lemonade (CITRON),
6 Yeats’ (Yeats = SA-ETY) work (= anagram indicator) about female (-F-) band (BELT) (SAFETY BELT) – how will that save you taking to the road? (SAFETY BELT),
7 Scott ran (Scott ran = CONTRAST) away (= anagram indicator) with distinction (CONTRAST),
13 Cycle (REVOLUTION) the route the organisers of the Easter Rising took (REVOLUTION),
14 Helpmate drops the (“helpmate” drops “the” = lpmae = MAPLE) syrupy type (MAPLE syrup),
16 It’s about (RE-) Health Check (medical) dismissing 100 (100 = Roman “C”) (“medical” dismissing “c” = medial = MEDIAL) (REMEDIAL) – and that’s intended to cure the problem? (cure/remedy = REMEDIAL),
17 Oxford (O-) and Victory (-V-) by Turner (Turner = -ERTURN) wrongly (= anagram indicator) (OVERTURN) set aside (OVERTURN),
19 Tweak (YANK-) drug (-E-) for Oriental (east = -E) (YANKEE) type of American (YANKEE),
21 Spring back (RECOIL) to record (REC-) from Greece (“Greece” = “grease” = -OIL) State (= homophone indicator) (RECOIL),
23 Rows (OARS) with some characters getting into Arsenal (some characters getting “into Arsenal” = OARS),
24 1000 (-M-) involved in strike (RA-P) (RAMP) coming down the hill (RAMP).