Both those answers look fine to me, especially if other answers fit in with them. I have actually seen that first clue before and the answer was Italian Vermouth then too (as in 'Gin & It').
I'm also with you on this...vermout(h) and confere(n)ce MUST be correct..
however, don't get 18ac "bartenders knock back endlessly on Sunday"...must be tapsters...knock back (pat=tap) Sunday = s ...then???