This is a great overview! Thanks for writing it. You note:

“When you create the event, your client signs it and then just publishes it to as many relays as possible, from where it will circulate into other Relays, consuming clients will republish them, etc.”

While this is true, the reverse is also true that you can limit your posts to select set of relays and choose where your content is distributed across Nostr. Of course folks may quote post it or repost it onto other relays, but for non-controversial topics, the relays offer an opportunity for topical or community based discussions. I say non-controversial because we can see in the comments here the fragile ego'd trolls do exist on Nostr.