Blackmagic Design Mini Converter SDI Distribution

What would b the best device to get the hdmi from a pc to the sdi input on this device?

I have two cameras to both send signal to one input on a Tricaster. Will this allow mw to do that?

I am needing a distance of approximately 600 ft. is it possible with this device & 2 300ft 3g/6g sdi cables? what is the longest?

Does it convert this sdi input to analog video output? or it just split the sdi into 8 sdi signals?