Across:
8 Rings Samaritans for Rosa (rings ‘SAMaritans for rOSA’ = SAMOSA) from Indian restaurant (SAMOSA),
9 Oriental (east = E-) former partner (ex = -XE-) sent back (= reversal indicator) to criminal (= anagram indicator) court (Court = -CUTOR) (EXECUTOR) – presumably, it’s The Job he got from Will? (EXECUTOR),
10 Couple (PAIR) of pirates set off (‘pirates’ ‘set’ off /without ‘set’ = pira = PAIR),
11 Opens 22 across (‘tour guides’ = TOUR-) in (-IN-) Government (-G) for No 10 (card) – for the most part (d) (‘card’ without ‘d’ = CAR) (TOURING CAR), it’s for the cross-border trips perhaps (TOURING CAR),
12 Red-tailed black sharks (FISHES) sound (= homophone indicator) almost vicious! (‘vicious’ sounds almost like ‘fishes’ = FISHES),
14 Give guns (ARM-) to the gangs (-BANDS) (ARMBANDS) for honouring the dead (ARMBANDS),
15 2 down (‘tour’ = TOUR-) gets award from College (first = 1ST = -IST) for diligence (INDUSTRY) (TOURIST INDUSTRY) in providing accommodation for the travellers (TOURIST INDUSTRY),
18 Still (STAGNANT), it’s a party (STAG- party) for mum’s mum (-NAN-) at the Central Hotel (central ‘hoTel’ = -T) (STAGNANT),
20 Assumes it’s true (POSITS) as Trim (p) old man (‘pop’ without ‘p’= PO-) takes a seat (-SITS) (POSITS),
22 Holiday reps (TOUR GUIDES) or pilots (GUIDES) after (= position indicator) 2 down (‘tour’ = TOUR) (TOUR GUIDES),
24 Prussian with no airs (‘Prussian’ with no ‘airs’ = pusn = SPUN) created The Web? (SPUN the web),
25 Heavenly (ETHEREAL) type at foundation (‘typE’ at foundation = E-) gets there (-THERE-) first to assembly (first to ‘Assembly’ = -A-) line (line = -L) (ETHEREAL),
26 Concerns of writers (THEMES) from border (-HEM-) seduced by set- (set) -back? (= reversal indicator) (set = T-ES) (THEMES).
Down:
1 Hay from Himalayas (‘hay’ from ‘Himalayas’ = imlaas = SALAMI) or sausage from the deli? (SALAMI),
2 Curator has no car (‘curator’ has no ‘car’ = utor = TOUR) for the sightseeing (TOUR),
3 Some churchgoing types (BAPTISTS) of graduates (Bas = BA-S) admit pressure (-P-) is initially terrible (initially ‘terrible’ = -T-) to get best possible result at university (1ST = -IST-) (BAPTISTS),
4 List of options (MENU) for the consumers of 8 and 12 across, for instance (for the consumers of ‘samosa’ and ‘fishes’, for instance = MENU),
5 A noble sort having an influence on The Speaker (HELIUM) is a lightweight involved in The Rising (HELIUM is the lightest noble gas),
6 Shades (SUNGLASSES) those seeing things for protection (SUNGLASSES),
7 Firm (CO-) ground (-LAND-) is fairly (half of) level (half of ‘tiER’ = -ER) (COLANDER) and, being porous, is incapable of holding water (COLANDER),
13 Where to find Basil (HERB GARDEN) in awful (= anagram indicator) danger (danger = GARDEN), taking time (‘time’ = ‘thyme’ = HERB) reportedly (= homophone indicator) from the start (= position indicator) (HERB GARDEN),
14 The big stars (A-LIST) in America (A-), similar to 4 down (-LIST is similar to ‘menu’) (A-LIST),
16 On holiday (OUT-), puts cards in the mail box (-POSTS) (OUTPOSTS) from remote parts of the country (OUTPOSTS),
17 Despot is (despot is = DEPOSITS) ruined (= anagram indicator) by what the financial institution is holding (DEPOSITS),
19 Occupied (AMUSED) by a (A-) thought (-MUSED) (AMUSED),
21 Took a course (TOURED) with writer (-ED) after (= position indicator) 2 down (‘tour’ = TOUR-) (TOURED),
23 Limits distress call (limits ‘DIstress caLL’ = DILL) to one of those in 13 down (DILL is in ‘herb garden’),
24 Look out for (SEEK) follower of Punjabi guru (Sikh) speaking (= homophone indicator) (‘Sikh’ = ‘SEEK’).