The CD is definitely live, and I personally believe they are not lip-synced. (The only one we have proof for is ANGEL'S SONG, but that was obvious even without the visual screw-up, lol.
)
No doubt they touched up the vocals at least a little, though, even if it was only to make the audio more crisp. They always do, be it a live DVD or a live CD (or, obviously, any regular CD).