That's cool. I didn't know about the .json URL trick.
After reading Sanger's post and both yours and 's responses, I think the only thing lacking from Hive is a private data and removable data. You have control of your data in that your keys can publish or edit posts. But, there are limits to what you can control. The public, immutable ledger prevents you from storing confidential data and prevents you from erasing your data.
I guess you could argue encrypted memo's fill the need for confidentiality. But, there's no hope from erasing data once it's in the chain (short of a hard fork).
RE: Response to Larry Sanger: What Decentralization Requires.