If you are auditioning for a musical, the song(s) you choose for your singing audition might just be the most important factor in whether or not you are chosen for the role. While we certainly hope the audition panel will not judge you solely based on your choices, the song you choose will impact how your vocal talents are perceived by the panel. You need to show not only the quality and beauty in your voice, but how you can use your voice to convey a character . Do not 'stage' or 'block' your song. All your energy should go into the emotion in your voice, not in 'being emotional' while you sing. Moving a bit naturally is fine, but don't plan it out. Remember that the audition panel wants to see and hear your singing in a singing audition. If they want to see you dance, they'll ask you to a dance audition.
Sing with accompaniment. I know some of us think we are such amazing singers that we don't need the piano, but we do. The audition panel wants to hear what you sound like with a pianist, just as you would in the actual show. If you don't have someone to rehearse with you, consider learning to play the piano well enough that you can prep yourself for singing with accompaniment.