ACROSS
 1. <converted image of> RASTERISED = ←DESIRE TSAR←
 7. <boyfriend> BEAU = "BOW"
 9. B_ + (A O B AB) = BAOBAB <growth in Africa>
10. <old-fashioned word> ARCHAISM = CHARISMA*
11. <full> CHOCK-A-BLOCK = HOCK inside CAB + LOCK
13. MIL LINER = MILLINER <worker dealing with Green Berets?>
15. _I BIS_ = IBIS <symbol of Thoth>
17. <expletive> DAMN = "DAM"
18. U_G A_N D_A N_S = UGANDANS <people from Kampala?>
20. <folk songs> SEA SHANTIES = (.i)SE ASHANTI ES(s.)
23. <tin-glazed pottery> MAIOLICA = M_C_A outside AIOLI
24. <perform> COMMIT = COMMI[-e] T
25. SCREENS HOT = SCREENSHOT <picture on computer>

DOWN
 2. <insurgent> ANARCHICAL = _ANAR_ CHIC _A _L
 3. <one avoided> TABOO = TAB OO
 4. REBU[-s] KING = REBUKING <scolding>
 5. (FROG + BRACHIOSAUR)* = SCARBOROUGH FAIR <song about impossible things>
 6. ←ROT COD← = DOCTOR <to fudge>
 7. <singer> BLACKBIRD = →"BACK BLURRED"←
 8. <part of church> APSE = A + ←ESP←
12. <dynamic> PIANISSIMO = ←(.d)OM IS SINAI P(e.)←
14. N inside LOG S WORD = LONGSWORD <melee weapon>
16. <shellfish> BARNACLE = BAR + NACL _E_
19. MANTIS, N_→ = MATINS <morning service>
21. (I AM) BS = IAMBS <bizarre, inane and obscure?>
22. <don't eat> FAST = FAT outside S