I noticed that my rims have a max PSI of 65 lbs but I have always run at 70-75 psi with Maxxis Load E tires. I run at 70 psi because the trailer has a max weight of 11k lbs. Should I be concerned ab...
Running 80 lbs on D rated rim is suppose to be dangerous. Putting "danger" aside running 80 lbs on rig who's weight is designed to run on 65 lbs will give you lousy ride. The max pressure on outside of tire isn't the weight that tire mfg recommends - that's based on the weight of the rig and in your case it's 65 lbs or maybe less.
I use E rated tires - D rated rims. Based on scale/weight my front tires are 48lbs and rear tire are just under 60.