A: This turbine has the ability to produce 1000 watts per hour depending on the wind, keep in mind in most cases this is hooked up to a charge controller and battery bank so you need calculations on pump running power required.
A: You can mount them at ground level, but want to get the thing as high as possible. Most of the time if you feel a slight breeze at ground level, you might have a a 10 mph wind at 30 or 40'.
A: Yes you can as long as your roof has sufficient structure, you will still require a pole that has clearance for blades and safety for humans to not be able to touch blades when spinning.
A: Mounting post is not included with the unit. The collar attachment designed into the base can accommodate up to 3 inches diameter for your desired post. The height of the post will be varied depending on your installation.