1. SACD/DVD-A are now available, as digital, on HDMI and, in my case, on 3xS/PDIF. The prior restrictions were based on the intention of keeping the digital output away from those who would copy it, allowing them only the analog. That should tell you something.
2. Well, the best justification of keeping it digital, for me, is not any dynamic limitations but the ability to make use of the DSP in modern AVRs and pre/pros, most especially modern roomEQ.
Kal