I'm pretty sure Altar Boyz doesn't rush on Friday and Saturday nights. Not sure about matinees. You won't be there on a Friday, so ... yeah...scratch that!
Anyway: Some pointers to help you stay safe in the theatre, in the case that you are among the posters here, who might tear you to shreds.

Kidding.
-Dress nicely! Attire is very important in most theatres. I would avoid jeans and T-shirts in most situations. Matinees are less classy, attire-wise, but evening performances should be dressed up for. Off-Broadway is also less strict on dress-code.
There is no official rule on dress code in Broadway houses, but it shows respect for the theatre and the experience of seeing a live show. If you stick out, you'll stick out in a good way.
I recommend going about the city in shorts and a T-shirt and then changing at the hotel pre-dinner and/or show.
- Talking. DO NOT TALK! This is one of the most aggravating things that performers and respectful audience members have to endure. Same goes for crinkling wrappers, flipping pages in your playbill, text-messaging or talking on your phone. It's all very taboo and you will most likely recieve death glares. I would personally try to kill you, if it weren't against the law. Just pay attention to the show, which shouldn't be hard.
One addendum: I do not say any of this to scare or hurt you. I say it simply to protect you and make you look like a well-educated theatre-goer. That said, I hope you have a spendid time in NYC. It's a truly magical place if you come in with an open mind and a full wallet!