Well, nipples showing is not big deal. Everyone has nipples.
But why on earth can't you wear bras - and long as they're not the balcony/uplift/underwired things, once you're a B-cup or over, you really need to wear one - especially for dancing! Surely a sports bra would be okay? Ask your studio why they object.

But there is a way around this - my daughter is an actor and a play she was in recently meant that she had to wear a skin-tight PVC cat-suit covered in slashes and holes - with no possibility of wearing anything underneath it. So she bought some nipple covers from a lingerie shop - loads of places sell them. These are daisy-shaped and really don't show, even under her PVC outfit!
They flatten the most annoyingly sticking-out nipples.

Good luck!

The only way to know if it is possible is to audition. I suggest you attend the SAB SI program and see if they invite you to the full time program.

*There are several rejection letters. As you attend SFB school it is likely they will recommend you audition again if they don't take you this time. I do think you would have a good shot at getting in in spite of the few extra pounds as you are only 13. If they think that is a problem you can work with the school nutritionist. Doesn't SFB school have a school nutritionist you can talk to?

*EDIT: As you just turned 13 days ago, you may be about to go through a growth spirt and that may be way you are not losing any weight in spite of all you may be doing. Don't worry about this too much. So few pounds at your age wont make a big difference. Had you been 15/16 then it would matter more.

If you do everything to learn it and you understand it outside of the test but still fail you are actually suffering from Atychiphobia. It's a fear that starts when you have to a test and you get the feeling your mind actually locks down, even though you know everything. Lots of people have it and it can be overcome but you are gonna need some help. There is a good chance they already have counseling or classes set up at your class to overcome it, so go talk to your teacher about it. Lots of times somebody suffering from Atychiphobia gets a little extra time to do their test so at least the pressure of having to solve you test on time is gone, which helps you relax enough to do the test properly. So my advice is to talk to your parents and teacher about it. And make sure you spend as much time on your homework as you do on dancing, then I think they will see that this is what you really want.

Source(s):

The reason you cannot do it is the same reason the flying kick in karate is the hardest movement to learn.

Humans are not "natural" in the air. Our legs are made to move on the ground and not in the air and you've been taught from childhood how to walk but not how to jump!

Taking a class in martial arts will help you "control" your leg movement better and rewire your thinking.

You probably feel "the stretch" when jumping right? It feels like you cannot move any more, before you have to position to land.

Everyone goes through that stage and it's actually your brain saying "ohshit I'm going to hit the floor!"

When you learn the skill of proper jumping, then you can calm this feeling and release your legs too.