Can apps update without Google account? Scenario:
- No Google account is attached to the phone
- No apps have been installed beside ones that where already on the phone (even after a factory reset)

Questions: 
- Is it possible to let the apps update without entering any Google account?
- Can apps update in the background when no Google Account has been entered into the phone?

I could not find this information in the FAQ.
No Google Account means no Play store.

And one thing is clear, if you don't sign in with Google account then it will not allow you to download or update any application from/to play store.