if you have multiroom or broadban unlimited then you can watch the live tv through your xbox for free. if you havent then you can only watch the on demand stuff and everything else is extra.
Nope i have the 8 meg version although i can use it wirelessly i get too much interferance so use the cable it costs me nothing more and we have 3 laptops a pc and the xbox not all going at once but usually 3 of the 5 without too many issues