3 - Does anyone sell just the USB-UART Adapter? I would love to just plug in my tube straight to the rpi but havent been able to find one yet.
I do. I just ordered all the parts so it'll be a couple weeks until I can ship, but if you're desperate I can tell you how to make one yourself with any commercially available CP2102 USB-UART adapter, although to make it look nice you should buy specific ones and swap SMD parts. Neither requires any equipment beyond a basic soldering iron, although SMD parts do require some dexterity and tweezers are nice.
https://bitcointalk.org/index.php?topic=882348.0--
novak