I think that a little post-processing on these pictures might work wonders. Since you have Image Editing enabled, I have taken the liberty of giving it a try. This is obviously just with [I]I[/i would do, you are entirely free to say that you think what I've done is rubbish 
1.
Black is only interesting if there's a contrast. Here I've boosted the brightness a lot, and taken out some of the red so that white looks like white, and skin looks like skin. Also, I've straightened and cropped a bit. To me, much more dramatic.
2.
Just a crop here. It's the people we want to see, get rid of the un-necessary black space.
3.
Again, crop in on what matters, fix the colours and brightness as in #1. I'd love to get closer in still; it's what the people are doing that matters and for this kind of picture they've got to fill the frame
4.
Again, it's about the people - get rid of the dead space
5, 6 and 7
Sorry, they'd be in my discard pile. #5 is just a plain ugly moment. Girls - dancers especially - look good when they are stretching. When compressed, they look fat and ungainly. And I am absolutely certain that these dancers are neither. The baggy vest top doesn't help either. The other two pictures just... don't work. For me, at least.
8.
I've tried to reduce the red and increase the contrast. If you'd given me more of the original picture I'd have cropped it, but I couldn't get a 3:2 crop that worked. However, I tried to increase the constrast in the top half of the histogram, to brighten the clothes and the skin, while making the lower half darker, blending into the dark background. I am seeing this girl as being a "baddie"...
For me, post processing is an essential part of stage photography. You only get one shot at it, and things are moving quickly. Taking the pictures into Photoshop and working with them can make a huge difference.
I hope you like the small changes I've made to your pictures; to me they make the pictures more interesting and exciting. But of course you may not agree!
regards,
/alan