Mouse turning is simply the default function of right clicking the WorldFrame to enable camera/character angle control. You don't need to do all your movement by the mouse though that is an option if you like. What is the key is that you are turning with the mouse because you can turn immeasurably faster than simply turning your character with left and right arrows or A and D keys. You are trying to do everything with your mouse but the key feature is the turning aspect and camera control (the mouse does this more efficiently than the keyboard because it can make large movements very quickly). It is still perfectly fine to use keyboard keys to do the actual movement of foward, back, strafe and even slow turn (if appropriate).
"In anything, if you want to go from just a beginner to a pro, you need a montage." /w TankSpot WTB Montage for Raiders.