Well, you and I are in the same boat. I've been using a Sony BDP-S300 Blu_Ray player as a transport for my headphone system because I want as few components in my living room as possible. The Sony is hardly the most efficient transport.
Regarding (1), I'm not sure what you mean -- do you mean selecting tracks using your TV and the player's on-screen display?
Regardless, if you were able to do it before you hooked it up to the DAC, you should be able to do it now.
Regarding (2), is this true of every Blu-Ray concert DVD you've tried or just one? After all, not all discs have well-recorded audio.
Regarding (1), I'm not sure what you mean -- do you mean selecting tracks using your TV and the player's on-screen display?
Regardless, if you were able to do it before you hooked it up to the DAC, you should be able to do it now.
Regarding (2), is this true of every Blu-Ray concert DVD you've tried or just one? After all, not all discs have well-recorded audio.