Audphile - let me answer point number 4 of your original post. Dedicated transports, often very expensive, offer very low jitter of digital signal. Average cheap player exhibits up to 3ns peak jitter what corresponds to about -85dB in sidebands it creates. Sidebands are very audible in-spite of extremely low levels, because they are not harmonically related to root frequencies. It creates "fuzzy" sound.
Many modern Dacs like Benchmark DAC1 have jitter suppression built in and almost completely ignore jitter (Benchmark has 3 Hz jitter bandwidth). Other than jitter and better mechanics I don't know of any other difference between expensive dedicated transport and cheap DVD player as long as it is bit transparent. DVD player might even have better tracking.
Many modern Dacs like Benchmark DAC1 have jitter suppression built in and almost completely ignore jitter (Benchmark has 3 Hz jitter bandwidth). Other than jitter and better mechanics I don't know of any other difference between expensive dedicated transport and cheap DVD player as long as it is bit transparent. DVD player might even have better tracking.