Microsoft Windows 8 App Store questions: login & app upgrade?

I have two questions concerning the Microsoft Windows App Store related to Microsoft Windows 8. I recently purchased a desktop computer for my son and a tablet for my wife, both running Microsoft Windows 8.1

Questions:

How can I use Windows 8 App Store without a Microsoft account? I only have local accounts on the systems, not wanting to rely on a Microsoft account. I have one, but I only use it as a junk email account (Microsoft does a pathetic job of filtering compared to Google & to a lesser extent, Yahoo).

Prior to disconnecting my account while setting up my wife's tablet, I tried launching Netflix to see how well it would perform at streaming playback. The app immediately indicated that an upgrade was available. Upon hitting the Microsoft App Store, I was presented with upgrading 23 applications. I tried to find a way to only upgrade Netflix, but there didn't appear to be an obvious way to only upgrade one application. How can I upgrade a single application? Does the upgrade of a single application present me with all the permissions that an application requires (similar to how a Google Market Place app request permissions)?

Thanks in advance.