i agree. i thought the extras were very interested and was disappointed to find so little, but I guess it's not really a film that lends itself to a million extras (like star wars or something)
in regards to the audio problem, if the audio is there on the original (which i assume it is!) and you doucle check that the boxes next to ALL of the audio streams are checked when you burn with dvd shrink then the tracks HAVE to be there on the backup.
have you tried using the audio button on your dvd player remote control while playing the backup? maybe it somehow set the wrong audio track to default. I'm not at home right now so i can't double check the disc to be sure, but if there's a DTS track, you will get silence if you don't have a DTS system.
try cycling through the audio tracks to see what's available as you watch the extras.
if that's not it then there has to be something wrong with the settings in dvd shrink. can you post a screenshot of your audio selections?