So you would have to download all content from the cloud onto your device? Apps, movies, books, music etc? Not feasible this would take far too long and would severely limit the space available on the device.

Right. I'd also add a general guest account where you, the device owner, can sandbox the available apps as well as permissions (no download, no installs, no cellular network data, etc.).

The device owner/admin should be able to create and disable users as required. If you have kids, you might want to create an account for the kids that only offers them certain apps and limits a number of capabilities.