Camera Control Drag Scroll options

Is there any way to configure "Mouse button drag scroll" to be inverted? The way this option works now is when you click down you sort of "grab" the terrain with your mouse and drag the terrain around. Having an invert mouse axis option in addition to the mouse button drag scroll would make it feel dragging the camera itself around instead of the terrain.

Without mouse button drag scroll checked, "drag scroll" (ie middle mouse click by default) lets you kind of drag the camera around, but there is an awkward dead zone to it. From what i can tell, the way this default drag scroll works is that when middle mouse button is clicked, a rectangular dead zone is made around your mouse that acts like the boarders of the screen for edge scrolling. When you move your mouse to the edge of this invisible deadzone rectangle, the camera edge scrolls.

All i want is to be able to middle mouse click and drag the camera instantly. Move the mouse up on the mouse pad and have the camera scroll up. Move the mouse down on the mouse pad and have the camera scroll down. Move the mouse to the right, have the camera scroll right. Move the mouse to the left, have the camera move to the left. I want to control the CAMERA with the mouse, not the terrain.

This camera movement option is in hots and dota. I'd at least like to know why its not in league.