This link may help. Basically, you can have:
Sound from HDMI in zone 1 with analog sound in zone 2
Sound from HDMI in both zones
And, of course, analog sound in Zone 1. This post seems to suggest that you can't do analog zone 1 with digital zone 2. Some receivers allow for this. Several Yamaha manual and official-type specs seem to say that there's nothing digital going to Zone 2 with the exception of HDMI on Zone 1. It definitely says there is no optical audio to Zone 2. I also saw somewhere else that USB/iPod won't play on Zone 2.

So when it comes to sources, if you want to be able to play from your set-top box (music channels?) while watching a different HDMI (like your Amazon cube) in Zone 1, you'll want analog from your cable box into the receiver.

quote:
Sounds like there is no way to have ALL my speakers playing same audio source. Am I correct in that?

That's actually the easiest- if you want to do this, just run:
1) Powered Zone 2 (speaker outputs) in to a 3-or-more pair stereo selector switch then to each speaker (with or without volume at each set of speakers)
This would likely be ideal for your receiver- your app can control Zone 2 volume from the powered outputs but not from the line-level ones
2) Line-level/RCA Zone 2 into either an external stereo amp then selector or line-level selector then 3 amps (which could be more stereo receivers) with or without volume control at each zone

This is where the "There are a bagillion ways to do this" comes from

Basically, if one digital and one analog source is enough for you, you don't need a receiver upgrade. But you will not be able to listen to HDMI sound in Zone 1 and Zone 2. Listening to the same thing everywhere makes it super easy, and your current setup would be fine (with some combination of speaker or line splitter/selectors)

There is essentially no way to listen to 4 different things with your current setup - you've never said you did want this, but I feel like it's important to mention anyway.

So, at most, how many different things would you like to listen to at the same time, and is there some way of making one of them come through analog and one digital? If the answers are "2" and "yes," you will not need a new receiver and don't necessarily need even an external amp, but you would have the option for it.