Hi Jenn... a few thoughts on your points...
JennB wrote:
1) My 50mm/85mm would be the best lenses to use because they're good for low-light/no flash photography.
Those lenses offer the wide aperture that you may well need to get an acceptable exposure in low light conditions.
JennB wrote:
2) Shutter speed should not go below 1/400. Experiment with 1/500 or 1/640.
Once your shutter speed drops below 1/500s, you will be more and more liable to motion blur. If you're looking to freeze the action then the faster the shutter speed you can achieve, the better.
JennB wrote:
3) Aperture should be wide open? Is this right?
You may have to work with the aperture wide open (or near to wide open) if the lighting is particularly poor. If had the choice of shooting action at 1/200s at f/2.8 or 1/400s at f/2, I'd definitely go with the latter. I'd rather have a few shots that are slightly out of focus due to the limited depth of field, than (potentially) ALL my shots rendered hopeless due to motion blur.
JennB wrote:
4) ISO should be a minimum of 800, but 1600 will probably be better.
You'll only be able to determine the ISO required when you are at the venue. It's all part of the exposure 'recipe'. The available lighting will dictate what ISO you'll have to use given the shutter speed that you want to achieve. Using a lower ISO should result in less noise, but not if you are underexposing. Try to nail the exposure. A well exposed image at ISO1600 will look significantly better than an underexposed image at ISO800.
JennB wrote:
5) Autofocus should be at Al Servo for moving subjects.
Yep... and, as the other posters have already stated, use only the centre point for maximum sensitivity and accuracy. I think Symes mentioned using the * button to focus (via CF 4-1). If you've used this setting before and you're comfortable with it, then great. If not then it may be worth practicing with this alternative focusing method before putting it into practice at an important event. Just a thought.
JennB wrote:
6) Use the M setting.
The lighting should be fairly consistent at an indoor arena... so once you have determined your exposure then you can set it manually. This will prevent the camera being influenced by dark/light backgrounds, dark/light uniforms etc. To determine the manual exposure settings, shoot some test shots. Bias your settings towards a reasonably high shutter speed (i.e. 1/500s) and then, using the histogram, see which balance of ISO and aperture give you a workable exposure for the ambient lighting conditions.
Ideally, you may choose to use a handheld meter or to shoot a grey card to give you a base reading for the manual settings, but chimping the histogram is certainly another route to success 
I would also agree with the idea of shooting in RAW. This will give you a small 'safety net' if your exposures are not spot on. However, be aware that it will slow your camera down somewhat as it tries to write the larger files to the CF card in burst mode... and, of course, RAW files shot at high ISO will produce significantly larger file sizes than jpeg images, so take plenty of CF cards with you.
Good luck with your shoot. I'm sure we're all looking forward to seeing some of the results!
---- Gavin