1. No. The Nextbox simply records the incoming video stream, commercials and all.
2. I think what you're asking is if the NB3 streams a live signal to other boxes. The answer is no. You need a box at every location to watch live TV, whether NB3 or the HD terminal.
You can watch RECORDED tv on any tv in the house with the Whole Home PVR setup. You need at least one PVR and one HD terminal. With that setup, you can watch tv recorded on your PVR on any tv in the house with a compatible HD terminal, and can set your PVR to record from the terminal. It requires a visit from your friendly neighbourhood Rogers technicial.
If you can connect an IPad to your TV, you can use the Rogers Anyplace TV Home Edition app to stream a small selection of channels....this would count against your internet usage.