CDDB is on disk, up to a point (about 450,000 titles). If it's newer than that, it needs a net connection to tag correcty

Yeah, but that assumes that CDDB information is correct, which it usually (okay, often) isn't. What are our options for fixing it? Can we update the track information ourselves? Can we update the built-in CDDB? Can we submit updates to the official CDDB? Can we use a different CDDB server? Can we update the on-disk database manually?

Also, can the device be used as a CD transport? That is, can it read the cdda data off the CD (or however you want to put/do it) and immedately send it over the TOSlink without reencoding it? Or even just as a normal CD player, sending the audio over the RCA cables?