1) You would only get Zone2 if you do not run a 7 channel main theater.
2) It does not offer the two back channels in mono, it is only intended for a neighboring bedroom to hook a stereo up to - and it allows the 5 channel main and 2 channel Zone2 to have different inputs.
3) Either way, the amp in this receiver will not handle being hooked up to a switch, or given very long runs of cable.
What I might suggest would be to dedicate this receiver to your main theater, or just be happy with only 2 zones.
Keep your eyes peeled for sales on pro audio monitors such as the JBL 3 series or PreSonus models. You don't need an amp, and between smart phones, google chrome cast, and however many other streaming services there are, as well as your home wifi, you can very affordably connect a pair of monitors to stream the same audio in any room. This solution also does not require running cables through walls!
Otherwise, if you DO want InWall/Ceiling type installations what you would be looking for is a Distribution Amplifier. Features and number of channels brings the price up very quick!