2) If they did would it even matter? Meaning, would the Rio be able to send the 5.1 signals through its RCA output to a 5.1 receiver?

The rio doesn't have a digital output, so there is no way it can send 5.1 signals to a receiver.

I doubt very much whether it has the CPU power needed to do the sort of thing you are talking about anyway. The CPU in the Rio isn't the fastest on the planet...