1, I had a 195rb and would not have thought of setting it up like that, the frame isn't that strong.
2. Get a couple of 2x10 boards, about 6' long drive the trailer onto them (one one each side) this will keep the tires out of "water" and make you feel better.
3. I would suggest for you to get some tire covers, install them, probably the best thing you can do for the sun and weather .
Do not worry about the hanging the tires in the air.
Any way you may have many awnsers ,but I believe jacking up and storing is a waste of time and effort..
BUT it will give you a chance to pull the bearings and do a decent grease job on them plus check out the shackels for wear and give them a shot of silicone spray. Oh and while you have it in the air, adjust the brakes.
THATs all from an old guy.
