I doubt very much you would be mining very much litecoin with a pie rig? prob not even worth the hassle
i'm willing to give it a try... do you know if it is possible to have more than one hub connected to the pi?
Yes, you can have a separate powered hub on each of the USB ports. I don't believe that there is a particularly large amount of USB data traffic needed to support mining.
Do you know if the pi 3 is a better option for setting up a rig? Do you know if the minera image file on other website work on the pi?