Each of the eight answers is a combination of 6, 29 teenieleek...eg 7D, look at the first three letters then the last two and how that ties in with the suprefluous words from 15A.
Thanks Ixion, 7dn and 26 I saw the two parts but I just didn't spot that they were all the same. Dozy I know. 23 took me ages to find the superfluous word but made me laugh when I spotted it. Enjoyed it.