Typically a VLive handset will identify itself with the VLive portal so it'll receive the content correctly rendered.
If you use a non-VLive phone, it might battle to display correctly. Best is to try it.
Video is streamed at around 200Kb/s (need to confirm). This, together with the resolution will determine the picture quality.
There is a fair usage policy of 3 hours per month, but this is a typical FUP setup, i.e. you won't easily trigger it.