Grit Dog said: "Grossly over inflated ties ( for the load, even if within max sidewall psi) can be almost as dangerous as under inflated tires in some (maybe different) situations."
I don't agree with this. Inflating a tire beyond what is needed to meet weight carrying needs is not a dangerous thing to do. It will most likely cause the tire to wear faster, but that is it. When the manufacturer prints the maximum carrying capacity of a tire at the maximum pressure listed it means that the tire is safe for this weight and pressure. If you have less weight than the max but you still air it up to max you are not doing anything dangerous.
Trailer tires are different from those you put on a motorhome. I agree with those who say, weight the vehicle and then pay attention to the weight capacity of your tires. If you don't want to run them at max pressure just make sure that you know the weight capacities at the lower pressures. There are lots of charts out there that will help you decide on a safe pressure.