I agree that 42a is YVES which is a boy's name (the equivalent girl's name is YVETTE). This is surely an error by the setter.
For 32d MARE & MAYOR are the homophones.
I cannot understand why 21d is TERGA but I have TERG? so it seems inevitable. I have identified the 12 homophone-clues so it can't be another can it? (GREAT / GRATE would result in TERGA but I can't justify them either)