how to stop dvd player from auto-launch w/ dvd insertion?

[Panopticon]

...and if none of the above 'stick'...

You can use 'Property List Editor' {Apple Developer Tools} or TextEdit to get into the DVD Player's prefs.
/Users/UserName/Library/Preferences/com.apple.DVDPlayer.plist

set {boolean values}:
AutoPlay = NO
AutoPlayOnDiscMount = NO

Save file, fix permissions.