1: Jumps all over bees swarming rat (7)
2: Behind and down and out (3)
3: Top-flight hairstyle instead (9)
4: Knowing in advance about 101 here (9)
5: Abstract art is just one step.(5)
6: Part, or bring together (5)
7: 27-across about starting off 1-down world unconditionally (2,3,2,4)
8: Strange red item showing black mark (7)
12: Criticise a computer analysis of famous passage (6,5)
14: Wrong, or sure one is wrong (9)
15: Conductor of opera rising in encore (9)
16: Doctor gives a new vault to the potentate (7)
19: Hot, current--'Gent' by Coco? Refreshing! (7)
21: Come to Korea - Chinese part (5)
22: Britannia - she never has blanched (5)
25: Sort of uninitiated cheat (3)