I had that same Palm for a long time, a great device.

As for POTS, I'd like to highlight what you've already said. You have a POTS phone pictured, but it's VOIP service (not POTS service). You did mention you could dial-up on a POTS service, but do you keep your POTS service active? I don't. The monthly fee is too much for my budget. I'll take the risk. By the way, if my cable service stays up, then that means I (probably) have Internet on my computer, along with VOIP.

What I don't see in your pic is a battery backup (which you probably have). As you know, that phone system does not work without power. My battery backup has kept my VOIP system running flawlessly during power outages.