1) yes, currently recording is always hub&spoke (and we don't have a real plan to support recording with p2p since it would require a substantial amount of changes in the server-side application)
2) no, recording is independent from streaming
3) no - I believe recordings are stored at the quality they are streamed. In theory you could re-encode audio and video stream to a lower quality for playback and repackage the zip file (assuming re-encoding the stream doesn't change the internal timestamps)
4) currently not. We are simply using the "zip" command (on *nix) to archive the files so in theory we could add the password/encryption option but that would require for you to store the required password on our servers and for us to pass it on the command-line making the process not very secure anyway.
Any specific reason to keep your archives on your servers encrypted ?