I think the paper work that came with mine, said to keep at least 10lbs of air in them.I also have Firestone bags.
I would look into doing something with yours. It's bad on the rubber to drive them with zero air in them, manual says to have at least 5psi in them. It doesn't raise the ride height, but helps protect the bags from wear.
Yes U WILL for sure!!!!That's supposedly legal in Arizona to pull dohbles with a class C license, but you'll definitely get pulled over in Oregon for that, regardless where you originated from.