More great questions, thanks!

I noticed you had used the site, so I tipped you.

It's still very early, so not much documentation yet.

To allow people to record their events permanently in the blockchain.

It's a rating to guess at whether it is a real and valuable user or a bot.

There's no block explorer yet, but you can run a Nostracoin node and query the blockchain directly if you like -> https://gitlab.com/nostracoin/nostracoin

It's a public blockchain!