I see most of that happening sooner or later. It's just a mattr of time for retailers to get on the same page instead of pushing in different directions. Retailers are usually not the innovators, but go with what equipment and technologies are offered for sale to them if they provide for advantages they didn't have before. I think Apple can give them that while keeping their investment in new equipment low.
On your last point, I think Apple should become their own payment processor, introduce mobile payment and authentication APIs for apps to use and integrate technology from their recent purchase of an indoor-wifi-mapping company into the APIs and services.