I'm not sure if you're looking for constructive criticism, or if this is more of a mkIII demo thread - but I'm going to offer some anyway -
A backstory:
I began shooting/contributing here about the same time as you (give or take), and was always a bit jealous of the gear that you were able to afford.
As you've specced up your gear though, the quality of your shots has not really seen the same improvement, and unfortunately these shots are continuing that tradition.
If I were you, I would be getting back to basics. You have the gear, you have the endpoint you're aiming for (live dance photography), now you need to work on finding the path to that endpoint.
If I were you, I'd be looking for something that has the same elements to the dance stuff but is more commonly shot (here at least) - and that's live music photography. There's a few guys shooting that here, some are not using top of the line stuff (break uses a 30D iirc), they are working with fast movement and difficult lighting - and they are getting some great results. Ask them questions, look at their compositions, how they use the little light available etc. Post specific questions about fixing problems in your shots if you can identify issues that you couldn't fix. I'd even be getting out and shooting live music as well just to get the practice in
I'm far from a pro, so take this advice however you will - but I'd like to see you improve and see some more of this type of stuff
As far as these shots go, I see a few basic issues:
* white balance seems off - most of the dancers look a bit green, but not consistently (eg #2 is warm). This is something you can fix in camera during your preparation by not using an auto WB setting, and adjusting it to suit the location before things kick off
* compositions are all centred - this is pretty boring, there are a lot of more aesthetically pleasing photographic composition options (rule of thirds, golden triangles, balance, etc)
* for the spinning hair shots, personally I'd prefer to see the hair framing her face than the back of her head
* the shots feel mostly underexposed - as mentioned above, I'd be working out ways to make the most of the little light you have available (positioning yourself differently etc)
* watch your backgrounds - most of the lights in the background are detracting from your subjects. They should be lighting your subjects instead
All of these issues are with technique, and not equipment based - you have some of the best gear available, now's the time to focus on the rest - good luck