For what it's worth, the terms of service have been updated. Not that it matters. As with everything on the internet, it's buyer beware and use at your own risk. For my part I'm comfortable with the underlying protocol and the role Bluesky (a public-benefit company) is playing in developing it and the reference implementations for it.
They have released a PDS (docker image) that will federate with their sandbox network. Federation with the production network will come after a period of time.
https://github.com/bluesky-social/pds
Federation still depends on three services hosted by Bluesky. Eventually it should be possible to consume these ATProto services from other providers, but for now Bluesky is the only one offering them.