ACROSS
1. <impressed by fame> STAR-STRUCK = S + TAR'S TRUCK
7. M→H in HERE = MERE <no more than>
8. ORAL outside (I + GIN) = ORIGINAL <innovative>
9. SHOO TOT outside U = SHOOTOUT <duel>
10. <organ> NOSE = "KNOWS"
11. B + OATER = BOATER <Panama [hat]>
13. <dangerous> UNSAFE = NEFARIOUS* - RIO
15. <deep> BASS <swimmer>
17. PICKER + E(-e)L = PICKEREL
19. SOONER outside CH = SCHOONER <boat>
20. <undiluted> NEAT = (-wi)NE A T(-reat)
21. C RY (←GOT← inside PRAM) = CRYPTOGRAM <code>

DOWN
1. HOSTAGE* = SHE-GOAT <nanny>
2. G inside (AG OO) = À GOGO <in abundance>
3. "SHIT ZOO" = SHIH TZU <small canine>
4. <rule> REIGN = "REIN"
5. C LASS IF IE DAD = CLASSIFIED AD <job offer?>
6. <software wizard> TECHNOMANCER = ENCROACHMENT*
12. <trash-talk> RIP INTO = (R O) outisde (1 PINT)
14. SUM outside TERN = STRENUM <breastbone>
16. <staircase leading to entrance> STOOP = ST OO + P
18. E leaves CAREER = CARER <social worker>