Jamie has it right, at least in my world.
I really hate changing strings, but I find that the pure nickel wrapped strings I use last many months longer than the nickel plated steel strings that came into vogue in the '70s. The brand I use is nearly as bright as plated steel, and has fewer 'springy' overtones. Supposedly nickel is easier on frets, which, if true, is a nice bonus, but that's not why I use nickel strings.
I do play all of my guitars (I only have a handful) regularly enough that I don't loosen the strings. I keep them cased, and use a humidipak in the cases of all my electric guitars. This keeps the relative humidity in the case at around 45%, which is ideal. The humidipaks seem to reduce the need for setups - I've needed none since I started using them about 6-7 years ago; By controlling the humidity in the case (they absorb moisture when it's humid, and release it when it's too dry) the strings don't corrode as much. The fretboard doesn't get dry. I don't put the packs where they can get squished by the guitar, of course.
The lemon oil people use on fretboards is merely scented naphtha - i.e., lighter or dry cleaning fluid. It actually takes natural oils out of the fretboard the same way it removes oily stains at the dry cleaners - what appears to be an oiled fretboard is actually the oils pulled out of the rosewood just sitting on the surface). So I use it only for cleaning (with my dry hands, maybe every other year or so) then wipe it off and seal the fretboard as PRS recommends (they used to recommend furniture polish; however they now recommend their own brand of tung oil following cleaning. Note that with tung oil you have to be careful to keep it away from the finished part of the guitar).
All polishes have abrasives and remove finish. That's how they work. Unless you're polishing out fine scratches, you're better off with the PRS Cleaner that doesn't have abrasives, but cleans and puts a nice gloss on the finish, and it's fine for nitro.
My motto is don't overdo it. All of my guitars are as close to mint as one finds in guitars that actually get played, so it's not like I'm careless.