GOOD NEWS! I have something to report...
Long story - short = YOU HAVE TO RUN THESE TESTS WITH X RUNNING!
This HTPC is an Ubuntu minimal install -- thus I have been booting into the shell for every change made to ALSA, nvidia drivers, etc. My HTPC was/is connected to the AMP and showing login info, etc on the plasma TV too so I thought this was OK.
I have gone back-forth-back-forth 100 ways over last few days and all the while cat /proc/asound/card0/eld#*
I also recalled seeing some HDMI specific info in the /var/log/syslog at certain points, but was never sure how/where it got there sporadically.
Anyways, saw some old Toshiba forum post about audio not working when not using the HDMI for video so I ran xinit xbmc and watched /var/log/syslog...It showed a bunch of new HDMI info, /proc/asound/card0/eld#* was no longer empty, and now sudo aplay -D plughw: tests work too!
Thanks for feedback Stephen; this was a greasy one.