From top to bottom:
Shadows On or Off (I'd recommend to keep em off. They arn't too well done and your shadow will be naked.)
Crit Zoom effect On or Off (Keep it off or you'll fail.)
Game Display - Window / Full Window / Full Screen
Vertical Sync On or Off (Only works in Full Screen)
Spell Effect Quality - Low, Mid, High, Auto
??? (It doesn't work...)
Skill Cut Scenes On or Off
Sound Effect Slider
Background Music Slider
Ignore Party Invites On or Off (Keep it off.)
Ignore Duel (PVP) Invites On or Off (Keep it on.)
Ignore ??? On or Off (I'd keep this on.)
Ignore ??? On or Off (I'd keep this on.)
Name Rotation On or Off
Dungeon Score Display On or Off
Second Skill Bar On or Off
Video Recording Codec (Mjpeg seems to be the highest quality.)