Well, your 2011 truck is pretty much nothing like the 2000 model. Totally different engine, chassis, body, etc. Your truck has a timing chain that requires less maintenance than the older truck. At 236k, he's overdue for another belt change

Fortunately for him, the VG33 is a non interference engine, so if the belt does go, it won't destroy the engine. How you drive them plays big into how they last. Otherwise, just follow the recommended maintenance intervals in your owners manual, and don't beat on it, and the truck should give you years of service.
No use of salt is a blessing...even with some stone chips, it's better than coating the truck with a substance that'll rust the heck out of it. Nissan truck frames are boxed, and when salt gets inside the frame rails, they get eaten from the inside out. Toyota paid for a lot of bought back 96-04 Tacomas because of this, and I've seen lots of older Pathfinders with the back half of the frame rotted away due to salted roads. I see no reason a wrap wouldn't work well as a rust preventer on the outside, but rust usually starts behind panels and works its way through, so an undercoating might be a better solution if you're concerned about it.
Keeping it clean is the best solution. If you have access to a hot water pressure washer to keep the junk buildup off the truck, that'll go a long ways towards preventing rust.