Came here wanting to ask the same as chrise re. 18a, so thanks for that.
I am stuck on 26down: T * H * ... can't see anything that fits, are my crosssers wrong?
And I have an answer for 12a that sort of fits half the wordplay and likewise half a def: a word that equates to I'm very pleased, but I don't think there's a thematic connection I can see. Nudges welcome, as ever!