Good stuff!

A question, in a world with millions of relays, how will clients work with that? Is there some kind of global relay database?

Because currently adding relays to clients its pretty manual. And by the way, I honestly don't understand why clients are not using all the possible available relays by default.

Wouldn't using all the possible avaible relays by default result in the most complete or uncensored version of all Nostr content?