I'm also looking for 2 audio zones. Best Buy website says "yes" for 2 zones, but the Sony answer (he answered this question) plus the manual says itt supports extra SPEAKERS (rooms, or "Multi room") vs. different zones.
Multiroom justt means you can play the same source in a different room (not ttwo different 'zones' such as movies in one room and listen to music in another).
So it appears this isn't the receiver i'm looking for, so be careful if you are looking for different ZONES versus just being able to play (or stop) the same source from playing in another room (a/b source).

There is a setting for bi-amp speakers called "remote" (I am not in front of the receiver, but I believe that is the setting name). That makes the two bi-amp speakers-the ones on your deck- operate by themselves. Otherwise, they will operate with the main speakers which may not be what you want. It took me a while to figure it out also.

Down load the online manual

I believe only certain speaker patterns allow for the use of A and B speakers separately. I have my speaker pattern under the speaker selection of the amp menu set to 3/2.1. I rarely use the speakers indoor so i usually leave that same setup for my indoor system even though it should can be changed to be better, but I would rather not change it each time I want to switch between A+B. If you want to switch back and forth between indoor and outdoor setup for the best setup then you need to change the speaker patter each time as well as the speakers selected. Hope this helps.

I've yet to implement a multi-zone setup, but form what I've read: ensure you have the matching cables (in case proprietary) and hardware and it should be as simple as adding more spearkers to your receiver.

You can select either A.F.D./2CH (located in from of your system) to determin which speaks to use. You can connect your speaker wires to any of these options in the back of the system. This is how I have my family room wired and out door speaks and it works and sounds great.

Use this help guide: http://docs.esupport.sony.com/homeav/STR-DH550_DH750/en/index.html

Yes, it works with 1 Subwoofer. I am using it currently in this mode.

Yes it will. Notice that it's a 7.2 channel AVR; the .2 is the sub. Simply means you can connect 2 subs to the unit.

Yes it will, my older receiver only had one as well and either output works.

Yes

Yes.

Yes. you can configure this as a two channel. You will have to select this manually or use the auto calibration for system to auto detect.

Just connect the speakers to the Left and Right channel behind the receiver and run auto calibration.

Yes you can. I'm currently using just 2 monitor 60s from Polk (slowly building my HT). The unit works perfectly in a 2 channel set up. That said I'd recommend you consider adding a sub, it adds a dimension to your sound field.

Yes you can. Use the front speaker connections and set all of your outputs to 2 channel.

I would use right front and left front.

Main Left and Right and use 2channel setup with large speaker setup