Alwayspuzzled - Your answers are right, I think.
7a anag of (w)ore L(evi)s
20a Ifor seems to have adopted a very feeble approach to the first phrase, simply juxtaposing a fairy with the defiined word which is the entry, or inserting the fairy in the defined word. This gives a non-word as the clue answer. Here the fairy is peri.
4d The definition for the entered word is given by the first three words, then the wordplay gives a 3-letter word hidden, reversed, in the next two words. The third phrase gives the rest of the entry.
28d This must be another use of the first phrase. I don’t know what the fairy is but the definition gives you telco, which is all you really need!
You must be right about the blanks, since the preamble says there are vacant cells in the final grid.
Nearly finished now!