Thanks, Semi, for your answer on the DVD-A.
Regarding my other questions... I did a quick scan of the AVSforum (which I do frequently visit these days), and what I see is that most people who appear to be "serious" about audio choose to connect the HTPC to their receiver/pre-pro digitally, just like you yourself plan to do. Such choice seems to me, as I eluded, entirely reasonable and probably superior than using an in-computer DAC. At any rate, those testimonials do not provide much information on the question about the analog-domain quality of those cards.
Cheers!
