Hi Tony,
6d is a three letter theme word (unclued) inside a three letter word for prompt. Think of service in the religious sense.
8a is a two self reference followed a three letter reversal (as was said earlier the Murdoch reference is not Iris)
That was a struggle especially bottom SE corner. Have finished but without parsing quite a few. Not your fault Boatman , just not on your wavelength!
No problem with special instructions if you buy the paper.
25a is SE corner so not sure where you need help! 25d is 3 letter theme inside 3 letter word for one who drinks too much, definition tap. 29a a 4 letter theme with usual one letter for daughter ,definition a Vandyke but not a painting.
28a are about a 4 letter word for boast with it inside!
20d word meaning to have a reaction to cetain things eg food, cats .plants ,still working on parsing!