Show off your voice.
Walk in and toss off something that nobody else can do.
I'm not one to do songs from the show you are auditioning for.
From your list Dulcinea seems good provided you can effortlessly nail those high notes.
Vocally for most of the principals Sweeney Todd is operatic and floating those high notes can impress.
Don't be afraid to build the tempo slightly during the song. It keeps it from getting dull.
What is Dulcinea about? Where does it climax? What are you singing about?
Smile. Relax. Don't apologise. Have fun.
Xx
"If my life weren't funny, it would just be true. And that would be unacceptable."
--Carrie Fisher