Hi Carl,
I'm using Wireless 1 in my home, and am relatively satisfied with it. I use it to connect my Beosound 9000 with a Beolab 2000 in an adjacent room (so I use Masterlink on both ends).
The transmitter and receiver units are in total about 8 m apart and separated by some wooden furniture and a door. Most of the times it just works and I can't complain, but now and again the music just stops and I have to turn the link speaker off and on again to make it work. It could be because of the relatively crowded 2.4 GHz Wifi band around where I live.
What surprised me is that there is no perceivable lag between the main room and the link room.
to answer your other questions:
1. yes, that's the idea. Provided your Beomaster has a Masterlink socket. I don't know if it has that.
2. I'm not sure that I completely understand what you mean. You can have several transmitters and receivers in one setup, but as far as I remember, the transmitters have to be spaced a certain distance apart. So I don't think that would work out for you. And remember: you need Masterlink.