I think Dumpynose has, deliberately or not, been a bit mischievous with the ambiguities in the unclued lights.
I am sure that slaney and Mysterons are right about 15A: JUDGE/see/C (or Dee/D) and NUDGE/gee/G are seductively close, but (for me at least) not as persuasive as BUDGE/jee/G.
crofter's suggested solution and homophone for 1A (LEADING ROLE and excel/XL, respectively) are neat, but don't quite persuade me. For what it's worth, I had LEADING NOTE and ti/T, but this leaves me short of one suggested homophone (10D suggests homophones of 2 members of the set).