You have a definite answer. The HVX's tape drive stores standard-def DV only.
If you want to hook up an external tape deck via firewire, then yes you could record HD to tape on that deck, but external DVCPRO-HD tape decks start at $25,000 so that's not the most common workflow.
no no no! there is no cheap and easy way to bypass p2/firestore/direct to computer.
- usb is not fast enough for capture
- firewire is, but stand alone hard drives arent going to work for live capture. thats why things like the firestore exist