E tires are a great upgrade for a half ton.
Don’t make it out to be a science project as some would have you believe. And they do not ride any rougher than P or XL tires if you adjust the pressure.
Whatever pressures you liked with the P tires, E will ride the same at only nominally less. Remember it’s air not the tires that hold the truck up.
Towing, you won’t adjust the front much if any. Rear, I can’t imagine more than 50-60psi being necessary to stiffen up most loads. It won’t hurt anything to run them stiffer except your fillings in your teeth! And maybe a bit of tire wear if you’re totally excessive.