Across:
8 Outlaw (BANISH) bar (BAN-) is (-IS-) near hotel (-H) (BANISH),
9 Cheating (cheating = TEACHING) problem (= anagram indicator) concerns those working at the institution (TEACHING),
10 Encouraging words (DO IT!) for half of 17 down (‘overdo it’ = DO IT),
11 Make up (make up/character = NATURE) title (BOOK) (NATURE BOOK) on the origin of species (On the Origin of Species = NATURE BOOK),
12 Robust (STURDY) writing (from the 3Rs = -R-) in analysis (analysis/study = STU-DY) (STURDY),
14 Let off (EXCUSE) for first murder? (first ‘murder’ = M-) It’s an eye-opener (‘eye’ opener = -E) (EXCUSE ME), begging your pardon! (EXCUSE ME!),
15 A number of dashes, for example (PUNCTUATION), for 24 across (‘mark’ = MARK), (PUNCTUATION MARK) period (PUNCTUATION MARK),
18 Endless (end ‘less’ = S-) epic (epic = -PECI-) novels (= anagram indicator) by males (-MEN) (SPECIMEN), for example (SPECIMEN),
20 Awful (= anagram indicator) line (line = EL NI-) doesn’t provide confirmation (-NO) (EL NINO) of strong Pacific influence (EL NINO),
22 Set down in black and white (DOCUMENTED) by editor (-ED) behind (= position indicator) paper (DOCUMENT-) (DOCUMENTED),
24 Banks making light work (banks ‘making light work’ = MARK) of grade from credit rating agency, for instance (MARK),
25 Potential private dinner date (army MESSMATE) in trouble (MESS-) with partner (-MATE) (MESSMATE),
26 Lads falling off sailboards (‘lads’ falling off ‘sailboards’ = siboar = ISOBAR) – it could be the pressure staying on a line (ISOBAR).
Down:
1 What one might take when taking leave (WAY OUT) is off the wall (WAY-OUT),
2 One of The Stones (stone/pip = PI-T) consumes new (-N-) (PINT) type of stout (PINT),
3 Whip (= anagram indicator) out hanky (out hanky = THANK YOU), as it shows some gratitude (THANK YOU),
4 Meant to leave statement (‘meant’ to leave ‘statement’ = stte = STET) and let it stand as it was (ignore marked correction = STET),
5 Some characters layoff a bricklayer (some characters “layoff a bricklayer” = FABRIC) in construction, in the building sense (the walls/floors/roof = the FABRIC of a building),
6 Car (-T) worker (MAN) found behind (= positional indicator) old Greek city (Thebes = THE BES-) (THE BEST MAN) is the pre-eminent supporter of The Union (THE BEST MAN),
7 Grass (INFORMER) with trendy (IN-) design (-FORM-) about (re = -ER) to be cut back (= reversal indicator) (INFORMER),
13 Meeting place (RACECOURSE) for ethnic group (RACE-) getting set of lectures (-COURSE) (RACECOURSE),
14 Consumed (EATEN) capers from Eastern Cape (‘capers’ from ‘Eastern Cape’ = eaten = EATEN),
16 The jury is still out on (UNPROVEN) a French (a = UN-) pastry recipe for starters (‘pastry recipe’ for starters = -PR-) in the kitchen (-OVEN) (UNPROVEN),
17 Is it to exaggerate (OVERDO IT) – party (DO) leader is (leader ‘is’ =-I-) consumed by what’s not under the table? (not under the table = overt = OVER- -T) (OVERDO IT),
19 Reviews (= reversal indicator) Hamlet, for example (Dane = -ENAD), for a (-A-) Frenchman (Monsieur = M-) (MAENAD) and a wild woman from Greece (MAENAD),
21 Usual (NORMAL) sod dug out of moorlands (‘sod’ dug out of ‘moorlands’ = morlan = NORMAL),
23 Aspects off the streetscape (‘aspects’ off the/ away from ‘streetscape’ = reet = TREE) from the forest (TREE),
24 Character (MOOD) on the periphery of Monaghan neighbourhood (‘Monaghan neighbourhood’ = MOOD).