I havn't used Tio myself. My wholesaler carries it and I had a demo. It was very impressive. The power supply is a brick which supplies low voltage that you can feed over your existing wiring.

I use Casatunes and Heos but given the Abus replacement scenario I would use the Tio for sure.

The zone players have line in/ outs and optical out I think as welll for when you use them outside the wall, connected as you would a Sonos Connect. Neat system.

I can't answer the Pandora question. It's not available to us in Canada but Tio is not Canadian I don't think. I can't see it not using Pandora. That would be silly. Admittedly I found their website a huge PITA to use. I recommend contacting them through the dealer page and asking for info.