First get a new pressure gauge, so you know what pressure is really in your tires. Too low with tubed tires will result in pinch flats. Use the pressure calculator at zipp.com. There's no reason for the rear tire to have 10-20 psi more pressure.
Best change I've made is to have frames that can use at least 28mm tires. Many now fit up to 32. Wider rims are also wise. I'm running the new Zipp 303s hookless rims that have an internal width of 23mm. With 30mm tires, I use 54/57 psi. The tires measure 31.5mm inflated.