We should derive some type of master identity system which could be used to generate new identities from a central key, like how bitcoin uses one key to generate many public addresses.

Only difference is it would have to use words and numbers, e.g. a key could be used to generate the moniker "gardenelectorate2501" and "jasmineponder7866".  This way usernames could be generated with one key, and the owner of the key could prove his various entities are his (but only when/if he wants to do so).