The A7rII would have to solve the lossy-compression issue, and hopefully have better batteries (it is ridiculous to have to purchase six batteries (as Lloyd Chambers points out).
Sony doesn't use bad batteries (they also make the Nikon batteries), they are just very small so they can fit in the small grip of the a7 cameras.
Dragging around 6 batteries is old fashioned DSLR thinking, the a7 series can be fully charged by USB in 1 hour so charge the camera in the field with a (solar) powerbank just like a smartphone, tablet, GPS, etc. While driving I hook up the camera to the USB charger when needed and at home I hook it up to the iPad or iPhone charger.
Going mirrorless isn't limited to just buying a new camera, it involves a complete makeover on how you deal with gear
You are spot on with the lack of 14 bits RAW though, they are working on it and the new a7SII supposedly has this issue fixed.