Good evening, Raymond.
You are on the right lines with 14ac..
The answer, of which you have the first word, is an anagram of "it only opera star", and is a genre in which Vanbrugh specialised.
For Id., take an American slang word for woman (5), add an anagram of " need" (4), and you have a synonym of "opened out" (9).
As for 2d., invert a figurative term (5) after inverting a synonym of "allowed" (3), and you have a mode of transport in Star Trek (8).
Hoping this helps!