15A Offering a sleep before dance(8): ?N??????S
18A On the throne expecting to be beheaded(7): ??????T
6D Catmint - ditto - above letter(6): E????
9D Certainly not rock's quality - or is it?(12): ?N????D?N?S? ( Unsturdiness?)
21D No cabin-boy(10, 2 words ): ??R?O?T??? ( Air Hostess?)