John,
To summarize what has been said in one sentence:
There is no concern for your electronics; however, running multiple speakers in the same room with the same signals significantly degrades sound quality.
The additional info you are offering does not change the above statement, and nobody likes to get in an endless cycle of repeating themselves. Slippery knows his stuff and gave you your answer. You can second guess all you want, but we are just reading and thinking "you can lead a horse to water..." If you don't want to drink, don't! But don't expect us to keep pushing your nose into the water!
The best argument for running multi speakers (with same signal) is for a large room where you want to turn the volume down very low (low background music) so the sound has some fullness without having it loud near the mains. It is not a bad idea for a quiet party where you want easy conversation, but still want music in the background. The signal is not loud enough, or is too blocked by bodies, such that the interference between speakers is not an issue.
You should definitely get rid of the extra speakers if you want to listen without loss of sound quality.
I should also confess to running multi-channel stereo in my living room. The room is central to my home and while I constantly pass through it, unless I am listening to music or watching TV, I never actually spend time in there. I find running multi-channel broadcasts the sound better throughout my home (into the adjoining rooms, like my office or the kitchen). It is also low-fi, but I haven't yet set up the zones to have good sound in my main rooms. However, when I actually sit in the Living Room, I switch back to Stereo for music or 5.2 for HT because it sounds better. Listen, you will hear.
