Bridgy Fed’s Bluesky integration is now in beta, and makes it possible to connect your account from the Fediverse to Bluesky, and vice versa.
There’s still some quirks, and every bridged account has to opt in to it, but it’s a promising moment for people that want to communicate across networks.
I don’t see any need for BlueSky at all when there already is a great network in the form of Mastodon. I mean all (most) of the ideas you mentioned apply one-to-one to Mastodon as well. To me they have very similar ideas.
Unlike ActivityPub, account migration with the AT protocol should allow to move content.
Mastodon’s moderation model is very different than BlueSky. BlueSky’s seems to be much better for targeted individuals and groups. But things aren’t entirely hashed out on either protocol or their implementations. We’ll see how it goes.