Wow this is a text book in how not to do it. You say you had an inspector look at it. Was he a National Wood Flooring Association Certified Inspector? He covered some items but doesn't sound like it. You need an inspection you can go to court with. Go to
www.nwfacp.org and get an inspector in your area.
Floors are bouncy, noisy, split boards. pinches feet????, cupped.
Acclimation: It can take 3 days or 3 months to properly acclimate a hardwood floor depending on conditions present. This can only be determined to be plywood. NWFA and most mfg's recommend solid 5" and over have a 3/8" serpentine construction adhesive on the opposite side of the nailed area to provide enough force to hold it down. Nailing schedule should be within 2" of each end of the board 6" to 8" apart. 14" you don't stand a chance of it not moving. No expansion space not a big surprise with those moisture readings the wood most likely has expanded if there had been no gap left cupping would be the least of your problems. The floor would undoubtedly be buckled 1" to 3" in the air.
If there is a difference of 1% or more from the top of the board to the bottom which it clearly states there is that they should not have installed it. Cupping is a moisture imbalance whereas the bottom of the boards are more moist than the edges. Could go down BUT with a moisture content of 15% to 21% in the subfloor unlikely it will happen even if you waited a year. NWFA recommends removal and replacement after the concrete dries to a Moisture content of 4.5% or less.
Any plywood with a mc of 12% or more dictates DO NOT INSTALL unless that area has constant relative humidity in the range of 70% or higher. Your average according to
www.wunderground.com showed an average of 36% when this was installed.
What would I do about this builder? I would get an NWFA inspection, present him with it and if he does nothing about it get a lawyer.
I've had two builders recently who when confronted with a certified inspection and a lawyer did the right thing.
This is totally unconscionable and should not be tolerated.