I haven't seen your monitor, although I've heard terrific things about it, and I'd say you've made a good purchase.This site
is a fantastic guide to using your calibrator. I'd start there. Your calibration targets should be 6500K white temp, 2.2 gamma, and 90-120cd/m2 luminance. (The luminance setting depends on your requirements, and the lighting in your workspace. I use 100, and it's great in my office. My advice is to err on the low side, even though it will seem oddly dim to begin with.)
Yes, I've used mine on a Mac many times, it'll be fine. However, it often doesn't work when plugged in to the keyboard USB port, or similar. It needs plenty of power, so plug it directly into a port on your computer.
No, you don't need to change your colour settings in any way. The monitor profile just does its work in the background, so to speak. You can continue to use Adobe RGB or whatever.
Now, settings. The EyeOne software only gives you a tiny bit of advice about your settings - namely, to set your Contrast to 100%. The rest is left to your trial-and-error. From my experience with many different monitors, I would suggest setting your Brightness, as well as the Red, Green and Blue settings, all to around 50%. Then run the calibration, and see what you end up with.
Basically, I'd try to keep all those settings in a "safe zone" between 30 and 70%. If you run the calibration, and end up with the Brightness too low eg 20%, then reset your Brightness, R, G and B settings all to 40% and run the cal again. Conversely, if you end up with a very high Brightness setting eg 90%, reset the Brightness, R, G and B settings all to 60% and calibrate again.
I know this all sounds a bit tedious, but you'll only need to go to this much trouble once. Subsequent calibrations will be much easier.
I hope this helps. Write back if you need more advice. All the best.
(Oh, there's a wide-ranging discussion about your monitor going on here
By the way, this:
never use the calibrator, but solely the calibration function in the Display system preferences on the MAC.
makes me seriously doubt this:
If they truly were experts, they would be following correct colour-management procedure, and would use the excellent equipment available to them.