I think that you are asking a lot of the remote, even with all it can do. I don't believe that its architecture is open or powerful enough to do this.

Z-wave most likely won't be the method to go concerning two-way control like this. WiFi is much more solid, as data can be dispatched in packets, resulting in a much more dependable communication format.

Z-wave is ok for lighting switches right now, as they are simply "on, dim, dim, dim off". Not much data there...

For construction of "if then else" conditionals, you'll need a system with more bells and whistles. RTI's XP-8 will 'eventually' have an update that allows for 2-way RS232 control. Pronto's RFX9600 allows for advanced RS232 now, and Prontoscript controls can be written to do a lot of cool stuff. There are already existing scripts written and usable for some Denon receivers. I am not sure whether they allow for the kind of control that you are talking about.

I'm trying to understand your wish list stuff. Can you be a little more descriptive with exactly what you want to do with the remote.

In my mind, you are approaching this backwards. I would program the remote so that it switches the audio format based on the source, and even on the channel, in the macro for the source/ channel. With that macro, you can then page flip to a page associated with the specific audio format.