i have 6 ohm speakers and use 12 feet each of 18 gauge wire. it works perfectly for the short runs in my space. you might try 16 gauge instead. the inexpensive stuff they sell at Lowes or Amazon works every bit as good as Monster cable which costs many more $ than generic cable. its all copper.
Yes you can. But to enable this you need to follow some steps:
1) Make sure that you have configured and enable Zone 2 on the setup
2) The source that you need to listen on the Zone 2 need to be connected using using analog cables (RCA). So if you want to watch you cable TV on the Main Output and listen to a CD from you DVD device on the Zone 2, this device need to have the analog cables also connected to the receiver input, HDMI audio cannot be routed to Zone 2.
3) Other option is to listen on Zone 2 the Onkyo Network (Pandora, DLNA, etc) or USB Device (MP3, iPod, etc).
On my setup I have connected all the sources using both HDMI and Analog (RCA) cables, and I'm able to listen any source on the Zone 2 indenpendently of what I'm watching/listening on the Main 7.1 Output.
Zone 2 only works with analog audio (RCAs), so the sources connected using HMDI won't be available to Zone 2. So in your example, you need to connect your Blue Ray to the receiver using both the HMDI and analog connectors so the audio can be available in zone 2, the same is valid for the other sources, the exceptions are the USB and NET sources that are internal to the receiver and are available all time for Zone 1 and 2. Hope this can help.