The light is amber while in standby, green while on, and red if there is a problem. My 3 200's go into standby after use at varying rates. Sometimes it takes as long as 10 minutes.
If you listen to a stereo source in 5 channel mode on a recewiver usually the signal is processed. You dont "lose anything", it just decodes the audio signal's dialogue (mid-high frequencies) to the center and spreads the rest of the audio to the other channels in a logical manner. This will vary slightly receiver ro reciever unless you are using a proprietary format like DTS Neo 6 or Dolby Pro Logic II.