I hope you won't mind me poking my nose in your thread, as I didn't take part in the competition, but the stuff about clue construction is interesting.
A while ago, I was lucky enough to get "A Clue to Our Lives" courtesy of the Guardian. This is what it says about indirect anagrams:
“Indirect anagrams are forbidden. For example, ‘Graduate never ordered plant (7)’ for VERBENA is illegitimate as you have to first guess that graduate is BA before doing the anagram; but ‘east’ to put an E into an anagram is OK. Just”
I know that the Guardian is not necessarily the last word in clue-setting, but its puzzles must count amongst the most respected by users of this site.