If I load up the KDVD template and then change the settings from CQ to 2 Pass , does this in turn render the KDVD template invalid, or does it still work under the 2 pass mode and would there be any advantage in 2 pass vs stock CQ setting of the KDVD template. My setting for 2 pass are 3100 4300 and 500 with padding.

Read here for the reason we use CQ and not 2-pass with TMPEG.
http://www.kvcd.net/forum/viewtopic.php?t=2073
Warning: Very long thread, but somewhere in there are the results

-kwag