Can I lift my Camper with a jack ? (pictures inside)

I would suggest that the next time you tow the trailer and air up the airbags, that you also air up the tires. Check to see what the pressure should be, but I'm thinking 44 lbs. You are at 7000 lbs, not including camping gear. I'm sure somebody here can tell you the exact weight that should be on your tongue, but I would think somewhere around 800 lbs. There should be some documentation as to how much weight you can carry. Maybe try towing without the Polaris and see how that feels.