[ger21]

If you use TurboCNC, I think you set the step pulse to active high in TurboCNC setup.
2) Sleep removes power to the motors, and enable does it in a similar way. You don't need to use them, they are bypassed (basically) when you get the board.
3) You have to plug in the 5V power steal cable berfore you can set the VREF. I think that is the terminal you were talking about in #5.

Plug in EVERYTHING before the motor power supply, And DON'T unplug anything while power is applied.

I would use TurboCNC to test the motors, not steppertest. It'll give you more control over the motors.

4) The power supply can be any voltage up to ~30V. Most people use 24V, though, because they are cheaper and easier to get. You don't have to do anything special to change to a different voltage supply. Just plug it in. Make sure it is at least 12V, though,

5) THere are no terminals for switches. You need to use the extra pins in either J10 or J11. See the Xylotex Home swoitch .pdf's. You might be able to use the 5V from pin1 of J11, and ground from pin 10, but I'd check with Jeff first.