I think that's possible, since all outputs are active at the same time. But you would be limited to the length of your cables. I have 4 TV's running off the same STB, using the coax out connector on the STB to feed to a splitter that sends the signal to 3 TV's, and the main TV is connect via component and DVI/HDMI. The coax out is limited to a signal of 480I, so it's not true HD.
Yes, you may. I have DVI going to my pj, Component to a switch box, S-Video to my DVD recorder, Composite to my Commodore monitor and coax to another room and all are hot at the same time, works great!