Across:
8 Crafty type (art) retires (= reversal indicator) (art = TRA-) from Russian body (Duma) – losing a leader (d) (‘Duma’ losing ‘d’ = -UMA) (TRAUMA) comes as a shock (TRAUMA),
9 Pursue a career (PRACTICE) at the end of 15 across (at the end of ‘general practice’ = PRACTICE),
10 Douglas leaves shoulder bag (‘Douglas’ leaves ‘shoulder bag’ = herb = HERB) for Rosemary (HERB),
11 The Band (BODY-), one of those in The Police (GUARD-) and One Direction (South = -S) (BODYGUARDS) – they generally don’t mind their own business (BODYGUARDS),
12 Gave out (ISSUED) to the children (ISSUE-) opening doors (opening ‘Doors’ = -D) (ISSUED),
14 Mate’s system (MONOGAMY) works for those who don’t enjoy wandering (MONOGAMY),
15 Fighting (army) tradition (GENERAL PRACTICE) one associates with doctors (GENERAL PRACTICE),
18 Shift (DISPLACE) is similar to 23 down (DISPLACE is similar to ‘oust’),
20 Superior (SENIOR) clip (t) posted (sent) (‘sent’ without ‘t’ = SEN-) around (= reverse indicator) Ireland (Republic of Ireland/ ROI = -IOR) (SENIOR),
22 Park (-P-) in old city (UR = U-R-) has a need for a rowing boat? (-OAR-) Having debts (IOUs = -IOUS) (UPROARIOUS), that’s priceless! (UPROARIOUS),
24 Expertise (GIFT) in a ward? (‘a ward’ = ‘award’ = GIFT),
25 They’re responsible for the mess (GENERALS) at the start of 15 across (at the start of ‘general practice’ = GENERAL-) and at the end of the process (end of ‘procesS’ = -S) (GENERALS),
26 No (no) going back (= reversal indicator) (no = ON-) to bar (-LINE) (ONLINE) where the surfers hang out (ONLINE).
Down:
1 Olive and Laurel (types of GREENS) take data from Great Danes (take ‘data’ from ‘Great Danes’ = grenes = GREENS),
2 Turnover (= reversal indicator), initially made (initially ‘Made’ = -M-) in type of bakery (bun = NU-B) (NUMB), is frozen (NUMB),
3 Turns up (= reverse indicator), support (aid = -DIA) starts with old boy’s (starts with ‘Old Boys’ = ob = -BO-) mother (Ma = -AM-) from college (C-) (CAMBODIA) in Asia (CAMBODIA),
4 Bottle in Christmas pudding (bottle in ‘christmaS PUDding’ = SPUD) produced by Irish Home Guard? (Home Guard = variety of Irish potato = SPUD),
5 It’s hard for a layman to understand (JARGON) Jack (J-) can be gas (-ARGON) (JARGON),
6 Get in line (STRAIGHTEN) for half-time (-HT-) stuck in flighty (= anagram indicator) gantries (gantries = STRAIG-EN) (STRAIGHTEN),
7 Muslim military leader (emir) briefly (r) (‘emir’ without ‘r’ = -EMI-) in Dacca (Dacca) working (= anagram indicator) (Dacca = ACAD-C) (ACADEMIC) with scholar (ACADEMIC),
13 A foreign (a = UN-) member of staff (employee) isn’t finished (e) (‘employee’ without ‘e’ = -EMPLOYE-) with department (-D) (UNEMPLOYED) that isn’t working (UNEMPLOYED),
14 Helpmate abandons the (“helpmate” abandons “the” = lpmae = MAPLE) syrupy type (MAPLE syrup),
16 The odyssey, for example (Homer’s The Odyssey = EPIC POEM), of direction (East = E-) for short film (-PIC) on Limerick (POEM) (EPIC POEM),
17 Judge (ASSESSOR) from Rosses (Rosses = -SESSOR) Point (South = -S-) area (A-) (ASSESSOR) going all the way back (= reverse all indicator),
19 A (A-) medium (-M-) in Middle Eastern country (Iran = -IR-AN) (AIRMAN) has head in the clouds perhaps (AIRMAN),
21 Switch (switch OFF-) at Terminus (-END) (OFFEND) or don’t get on at all (OFFEND),
23 Get rid of (OUST) some deciduous trees (some ‘deciduOUS Trees’ = OUST),
24 Big swallow (GULP) around (= reversal indicator) Cork (cork/plug = GULP).