1" black poly pipe would do you just fine.
Depends on weather or not they are 1/4, 1/2, 3/4, or full circles. 2.0gpm would work, and you would have to adjust watering time
The compressor we used were tow behind air comp. we used a 135cfm and a 185cfm. We kept the pressure at 65-75psi. You need flow not pressure
If you using rotors your going to want to make sure you don't go over your 7gpm limit. I would say three 5004 rainbird rotors with 1.5 gpm nozzles in them per zone
Your going to want to find a compressor that has a high CFM (cubic feet minute). Depending how much time you want to spend doing your B/O, for a normal system 135cfm is a good place to start. you can use a compressor like the one you were asking about but it will take quite a while
