We have the same unit, no sway. Tires 75 front, 65 rears. Travel lightly loaded with about 15 - 20 gal, water. Overtaking trucks do not bother us. Our driveway is steep, but no problem with dragging.
The castor cops will be along shortly to recommend changing castor to +5 and getting an alignment. I have done neither.
I would question the air bag usage for just the driveway clearance problem. That would mean you would need to air up at the bottom of the driveway each time. For me, it wouldn't be long till I just left them filled.
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