Yeah, I was thinking the same - that this could be a password manager as well. I have built in the ability to store private records. I use NIP-44 to encrypt but could easily add in the AES password encryption as you suggest.

The big idea is that this ‘thing’ (safebox, password manager), via relays, can live independently anywhere. I’ve already started to build a replication functionality to move it to other relays. IMO that’s a big advantage over any cloud service, or even a self-hosted machine because it could fail, or your house burns down.

Anyway, still early days of heavy experimentation. Thanks for the comments!