I've just read most of the thread. Interesting idea. I have a 13,xxx above ground pool, live in northern Maryland (~10 miles from PA line) and my pool never truly freezes (at least not to where I could walk on it, unless it's a really bad winter). I converted to a saltwater pool for convenience (2800-3200ppm). I don't leave my pump running, but because it's a variable speed pump, I could for little money all year long, but instead take the pump inside. At its lowest setting it moves water and uses 70-80 watts. Pentair makes an economical VS pump for $650, but with any VS pump in Maryland there's a $400 rebate from the electric company, so $250 total (+taxes).
The salt I get is from Home Depot @ $4.99 / bag. Sometimes I can find it cheaper, but because salt doesn't evaporate, it's not a big deal. I usually have to add a bag after the winter season, although this last year I didn't and everything was fine. This is with multiple kids splashing like it's their job.
I picked up a cartridge filter on CL for free and the cartridges were still good. This prevents un-needed backflow. Coming from a sand filter, I feel it does a better job (it's way over-sized for my pool, made for a commercial sized swimming pool). So far, I clean the filter once a year. It is more of a pain to clean the cartridge than sand, but that's far outweighed by only needing done once / year. Pool water stays crystal clear, needs vacuuming every so often.
Just my experience, not sure if that helps, but for what your doing I don't think it needs to be to extravagant.