I think that mono/stereo issue depends on the modulator. The one that I have has both R & L inputs.
As far as video distribution, that's a tricky one. The track you are on will work, but you'll kill a channel (3 or 4) on every TV in the house, unless it's in-line w/ a particular TV only. Also, you end up having to try and find ways to control the central units remotely, which can be tricky. Alternative methods would be to do media hubs, such as Prismiq and others that have popped up recently. They will do video, but you will need to have the house networked in some way and have PCs acting as servers for that content.
I'm sure that there's more in-depth solutions out there, but they might require some heavy installation of components and perhaps additional coax/cat5 runs.
You may want to poke around over at the
AVS Forums and see if you can find some more help with this. They have a home automation forum that might help.
Good Luck.
