1) any frequency below 750 Mhz "should" work. 2) In the 2nd JPG (nice dwgs by the way) I think your OTA signals could or will conflict with any Ka signals which might be coincidentally present. Stick a BBC inline at the output of that multiswitch and you would (conceivably) solve the conflict, at least in theory. 3) the only thing confirmed so far is death and taxes. Right now we don't know the answer to this. 4) I'm guessing they will, no reason not to think they wouldn't manage the bandwidth spectrum the same way. I don't think anyone has yet proven that the idea will work with those receivers with built-in B-band convertors.