1: The pole will carry the principal mainsail (5)
2: The king did not stand for it when he heard that he ogles her. (4, 3)
3: Get cosy slip due to fray (5,2)
4: Zero writing for 'humble' Wilbur's speech? (7)
5: 3-down said Sir, I have these! (5,4,4)
6: Wreck plastic cup rack (5-2)
7: Treated badly, lost skin covering back (7)
9: Finish suddenly, like an oboe? (1, 4, 2, 3, 3)
16: Actually, 17th century author's unfinished play is included (2,5)
17: Lighter note: tin soldier's back (7)
18: Grant again drew one crookedly (7)
19: English post-punk singer was very determined. (7)
20: Final recipient of product ensured indiscreetly. (3, 4)
24: Farm branches, in part (5)