- The places NIP lets people own their location and edit it: https://github.com/nostr-protocol/nips/pull/927

- it also will allow for OSM tags to be applied to nostr places by the owner or by crowdsource; the client decides how to interpret these

- "official" places have the same problems and solutions that "official" identities have. Verifying a pubkey gets you the official location if such a thing exists. Other heuristics can filter lower quality places in favor of better curated ones, or high quality place-serving relays can supply a good base map. Many ways to do this.

- generally, I don't see a need to tie anything to OSM. I'd rather see people copy places that matter over to nostr. Satlantis.io is doing this using the Places NIP.

I wish I had time/money to work on this but things haven't worked out.