Actually the mplayer CLI arguments I provided were only examples to demonstrate how the config file works. You still need to figure out the proper CLI argument for changing the audio-video delay. Try doing a text-search around the mplayer man page.

Just to explain my example mplayer arguments:
-af is "audio filters", which I thought was a good candidate for where the audio-video delay spec MIGHT be
-ao is "audio output"
-fs is "fullscreen"

Good luck,
Justin