Why not have a category of "light" accounts for newcomers; allowing them to use Hive on a simplified basis, while the original account creator holds the keys, and the new user only gets the posting key and if they lose it, they can still recover it from the account creator.

Such users can even see their Hive growth (including rewards), but they can't do anything financial until they agree to a "full" account, at which point they get the keys from the account creator, who then shreds them.

It's basically a variation on the widely used "freemium" model.

Additionally, if someone starts a "light" account, uses it for a while and then abandons it... maybe after a year, the keys could be shredded and any unclaimed rewards burned.