I'll answer them in order for you.
1. You can apply some waxes with a DA but by hand is much easier. Dodo Juice have a wax called Supernatural which is available as a "machine stick".
2. Yes, you glaze before you wax.
3. Yes you have to wash the pad's after every session. You do not want dirt sitting on your pads as you will only end up scratching your car if you don't.
Hope that helps,
Chris