I didn't get to this until yesterday and given the absence of a thread I think I must be the only one finding it hard. I have all but 1 of the answers - 12 down (You shouldn't have espouser flogged dead[5]) is completely eluding me - and I think I've gone wrong with the moral tale. I was thinking along the lines of porcine and lupine characters but that's obviously wrong. Any hints for 12 down and the theme would be much appreciated.
I don’t remember the clue, but the wordplay clearly points to two-letter informal for thanks, you shouldn’t have, then three-letter espoused (not espouser), giving the past tense of an obsolete word for to flog