1. The issue of whether HDMI or 5.1 is "better" depends on the signals you are concerned with (does your player decode and/or transmit the HD audio tracks?) and whether you want to use the DSP/bass management in the processor. I believe that, with modern equipment, it is advisable to use HDMI and let the processor handle as much as possible.
2. Should be no difference between coax and optical.
Kal
2. Should be no difference between coax and optical.
Kal