  Hence, the future it shows is not taken from a Mirror World, but rather from the the data of the previous occupants. Thus, the future is completely made up, but also incredibly likely - potentially not taking into account the alteration made to it by its own act of showing the future to Aviendha.  I'm okay with blood-future visioning, although I'd suggest that such a thing would be highly speculative, as far as showing a real, likely future (unless you believe that bloodlines can span Turnings accurately...or if blood lines end at the end of the 0th Age...but anyway).  It wouldn't be capable of taking into account other world-wide events, which is why I don't believe you can get the future visions Avi saw without more than blood ALONE.  Also, you note that Aviendha breaks the machine, but then you don't accomodate room for the idea that in breaking it she changed the inputs, she made it into something it wasn't...