Yes, your questions are correct. When running that much dead head you can set the pump to max pressure to get the most at the jet face.

Anything higher than 185psi and the valve will have issues with slower opening which is a bad thing.

One thing to keep in mind is not to get too overly concerned with the exact cc the system is putting out, but to see how the car responds to what you have. If you need a little more on the top end turning the gain up a little should help.