You ask a few good questions, and I'll give you my thoughts one by one.
First of all, spend an evening on this site. It will be time well spent:
Here is another GREAT spot for lighting info:
Now, onto your questions:
-how many frames per second are you able to get using the 580 with the settings you have outlined?
I use an external battery pack to power the 580EX, a Quantum Turbo 2x2, which allows me to get 2-3 fps. However, fps isn't all that important and, like shooting in the daylight, I don't recommend relying on it to get your shots. Timing the shots is still preferred. In fact, I set the cameras to the slower burst rate just so I don't "overshoot" the flash. With the external battery, it IS possible to fire the flash so frequently that you'll fry the flash head - I've seen this occur. Plus, if you set the flash to the highest burst speed, no flash can keep up with the camera, and you WILL miss shots.
-Is it possible to use a slightly faster shutter speed?
You can only sync up to 1/250s with the current generation of CMOS sensors (20D-40D, 1D MkII - 1D MkIIn - I hear the MKIII sync's at 1/300s but I haven't used one). The original CCD 1D sync's at 1/500s. So, to answer your question, unless you shift to HIgh Speed Sync (HSS) on the flash, things won't work well if you raise your shutter speed higher than the sync speed. You'll see lines across your images, and all manner of bad stuff will happen.
So, what is HSS? This is when your flash fires at a much higher speed - it actually fires a series of very high speed pulses rather than one continuous pulse. Because of this, and a few other factors, when you're in HSS mode, and running shutter speeds > 1/250s, you lose a LOT of range. See this explanation for more detail:
HSS can work OK, and I use it from time to time, but I tend to avoid it. It also lengthens recycle time for the flash, which cuts down on fps, and uses up power at a far greater rate, so your batteries won't last as long.
-Is it possible to use the flash to compliment the stadium lighting rather than replace it?
You might think this is a good idea, however it can cause more problems than it helps. The primary reason why you want your flash to be your dominant light source is that when you use flash, the duration of the flash burst is a lot shorter than the duration that the shutter is open. The flash duration of the 580EXx, at full power, is around 1/800s. As you reduce the power, the duration goes down considerably. In other words, the flash gets faster.
Why is this important? This faster duration does two things for you. One good, one not so good.
Firstly, the good: it can stop the action better than your shutter speed. You read that right - even though your shutter is set to 1/250s, you can actually get 1/800s (or faster if running at lower than full power) worth of effective action stopping.
Now the not so good: because when your flash fires when the shutter is open it exposes the sensor to its light. This is exactly what you want to happen, and why you use the flash. However, if the ambient light is close enough to the level of the flash, you run the very real risk of getting two exposures. Your sensor exposes once for the flash at, say 1/800s, and another exposure for the ambient at 1/250s. The result of this is a sharp image at 1/800s from the flash, and a slightly more blurry one at 1/250s, superimposed on each other. Not so good. You get a "ghost" image surrounding the sharp one - VERY annoying.
For this reason, I set my flash at least one stop higher than ambient, and if I see any ghosting in my images, I either up the Flash Exposure Compensation if I'm in ETTL mode, boost the power if I'm in manual, or dial down my exposure (dial down the ISO).
That's not to say you can't "finesse" mixing flash with ambient - just be aware that when you do this you might run into ghosting, and if you see it, you'll need to know how to deal with it.
Another good reason for having the flash be dominant is that you can avoid the funky white balance issues that come from the lights cycling in gyms (or even in stadiums). Here's a great discussion of light cycling:
As for shooting manual (flash and camera), a trick I learned from another shooter is to shoot a series of images at various exposures (keep the aperture and shutter speed constant and vary the ISO) until you can JUST see the players - they'll look like shadowy ghosts. Leave the camera at this setting, and then turn your flash on at maybe 1/8 power, and move it up from there until your histogram shows some info on the right half. Shooting manual flash and camera can yield optimal results, but you'll need to adjust the level of your flash as the distance to your subject changes.
I have been told that strobes are sometimes installed at facilities, especially basketball courts and I have been trying to figure out if there is a "poor man" solution that might be comparable.
Many pro and college arenas have strobes installed. These are VERY powerful and VERY expensive. Most of these are "permanent" and available only to team photogs, AP and Getty dudes and maybe SI, et. al. The rest of us are on our own.
Here are a few links with more info on this topic:
A lot of us who shoot High School basketball and hockey will also install strobes temporarily (like White Lightnings or Alien Bees, for example) but even this isn't a "poor man's" solution, as it can cost a couple thousand bucks. I have had pretty good luck using my camera flashes mounted on flash stands, fired with Pocket Wizards (the most expensive part - these can be replaced with hard wiring, which is a LOT cheaper, but creates trip hazards) and found that this works remarkably well, and is very quick to set up and break down.
Check this out for starters:
I have been struggling to find "howto's" on the subject of sports photography using flash or
- is this something that can be done in other ways and, if so, what are your experience
Hopefully the info above will help.
Finally, what power solution(s) have you found work best for you with the 580ex?
I've had good luck with the Quantum Turbo 2x2, but it's not cheap. I have used it to power my flashes and my camera bodies, as it has two output ports.
Others have reported good luck with the Black Box
and the Dyna-Lite JackRabbit. The Canon Compact Battery Pack CP-E3 is another option for just under $150 that uses AA batteries.
Hopefully this will get you going and well on your way.