When I had my 2011 F250 I installed the same equipment you listed, RideRites and AirLift 7200 compressor. My fiver is pin heavy and I load it even heavier. It puts over 3000 on the truck. I experimented and found 55psi worked perfect for my set-up.
It is very easy to figure out. On a flat surface, paved if possible, measure the bumper height of your truck at both ends and record this. Hook up the trailer and remeasure it. If your front went down then the rear should end up the same distance lower as the front went.
Say the front measured 20 inches and the rear was 28 when empty. After hitching the trailer it measures 18.5 at the front you would air the bags to get the rear height up to 26.5 inches. The whole truck has dropped 1.5 inches but is sitting at the same angle as before - just lower.
I used the license plate on the front and the top of the bumper in the rear as my reference points.
Do this and you will know what pressure is best for your situation. The truck will drive the same and the headlights will be aimed correctly.
My F450 only drops 1.25 inch at the rear so I have done nothing to that suspension . I did lower the headlights a little.