Correction - caller ID stopped working on my nufone account on 2/10, and they say that nothing changed at their end
Looks like they are revamping their web site, and the new (still beta) site has a field to enter whatever caller ID number you want, for each account. Also switching proxy servers, etc. - it looks like I have some work to do, to go through all options, setup a new device on the new proxy servers, and hopefully, all will be fixed
The DIDs now can be set by the user to go to a device registred with nufone, a PSTN number, or some arbitrary SIP account, with a fallback position (same options) if your primary does not work. You can have a DID going to your FWD account or * box, and if FWD is down, you can have the calls going to your PSTN line.