Nitpick:
So there are. And they are right.

After all, the N8x0 has 2 peripheral interfaces, BT & USB. RS-232 adapters are available for both of them. So, in theory, any phone that may be tethered by BT, USB, or RS-232 may be tethered to the N800. (Software req'd may not be ported in some cases, of course.)
I believe I did see a report indicating that someone had made a USB-link tether work, not sure though.

Still, point taken, there are some who have no clue (i.e. do not realize that the phone must be BT or that they must be hackers), and resources to help them would be nice.
As texrat says, sounds like a job for the wiki.

As for troubleshooting sessions, those could go in the "Troubleshooting" forum? Hopefully with any resulting tips placed in the wiki for further reference.