I think they do still service the D7200.
https://repair.nikonusa.com/en/ProductEntry?_gl=1*8o2e1e*_ga*MTI4ODAzMjQwMy4xNzA2NzIxNDA1*_ga_X6M3D0X6CX*MTcwNjcyMTQwNS4xLjEuMTcwNjcyMTQyMi40My4wLjA
Wife and I each got a Nikon Z7ii, also both got a Z 24-120 f4 lens. Sharing new Z 70- 200 f2.8 and 2x teleconvertor. Have a small learning curve ahead. To get used to this vs. my D500.
I think these are excellent representations of the GC. I especially like the first / color photo because it (for me at least) shows the immensity of the sky, which dwarfs even the canyon.
My wife got a D3200 to play with years ago. Battery life was crazy short, so bought a replacement battery (store didn't have a Nikon version so she bought an off-brand, not sure which one). That one lasts 10x as long as the original Nikon battery. Maybe the one you have was just a factory dud for some reason?
I found this to be interesting:
https://www.digitalcameraworld.com/buying-guides/the-best-150-600mm-lenses
If you want to be a better photographer, practice, learn, practice. If you want better photographs, the second (or lesser) thing is the equipment. And there are lots of fine mirror and mirrorless equipment that will give you the opportunity for great photos. Look at John Muir's photos -- none done with the new mirrorless cameras.
I also have had no issues with SnapBridge on my iPhone and D500. Is your iOS and snapbridge software up to date?