I highly suggest getting your weight checked and inflate according to the tire manufacturers recommendations.
When I picked up my 350TS they had all the tires inflated to 95psi. It road very hard. I think the wall sticker says 90psi but you should inflate them to the tire manufacturers recommendations.
I have Michelin 235/80Rx22.5 XRVs
Michelin RV Tire guide can be downloaded here: http://www.michelinrvtires.com/miche...e-material.jsp
Ideally you would do a 4 corner weigh but most scales only do per axle.
On a recent trip I was loaded to the gills headed to SD/Wyoming for 10days. I weighed at a flying J since I felt I couldn't pack any more stuff in if I tried and this would be a good baseline. I measured 6780lbs on the front axle, 14280lbs on the rear axle.
Consulting the RV guide I could run 75psi on the front and 85 on the back. I added 5psi safety margin, since the weight on each corner could be different, but the ride is much much better than the way it was delivered. Most of the comfort came from lowering the front tire pressure.
A side note about weights: Loaded up at 21,060lbs means I had 2330lbs of water and stuff along (350TS ULVW is 18730lb). I still had 940lbs of capacity left but....my towed, a Ford Edge AWD LTD weighed 4560lbs at that scale. So on that trip I was within 380lbs of my GCWR of 26,000lbs. Too close for me, so I have endeavored to loose some junk and get my weights down.
It sure has a comfy, quiet ride with that much weight and correct pressures, but once we were over 4000ft in Wyoming I was wishing there was a turbo diesel under the hood.