If you look carefully at the back of his truck he has a tow hitch - never lifted and slewed off a hitch? No - hey you haven't lived.
I know a bit about rock salt - we use it here occasionally. Regular maintainance will prevent too rust and keep the jack moving
With all due respect, I would not recommend jacking up the truck from the rear hitch especially to change a tire.
1. You have to Jack up the entire rear end of the truck vs just one corner. This is inherently more dangerous and prone to slipping
2. The OP is unlikely to use straps to limit damage caused by hi lift sliding out
3. The only time to even consider jacking from a rear tow hitch is if you are high centered and have nowhere else to Jack.
4. Changing a tire where that entire axle is off the ground is about the riskiest thing you can do.
The force required to Jack one corner off the ground is considerably less than the force required to lift the entire rig off the ground. You are playing with fire here.
To your last point prevention is far better than cure. I wouldn't leave a tool out in the elements even if I did maintain it regularly. Why have the added concern that it could fail. Especially on the trail. Or worse still even if youndo maintain it and get into some mud on an extended trip, the mechanism could seize. Not something you want to deal with. If we all focused on prevention as opposed to cure we wouldn't have as many breakdowns and casualties when exploring.
Additionally if you want to elucidate the finer points of maintaining a hilift to the OP be my guest. Know that most people with hilifts don't service them. And those that do service them often don't permanently mount them outside on a low hanging rear bumper.
-Sam