1) I don't think the problem is scrolling speed, but more like the "Delay" when you brush to the edge of the screen. That should be configurable.
2) Also the scrolling is "Jerky", it goes fast, but doesn't appear smooth - even after you scroll around and preload the stuff. Perhaps "Smoothing" it would get rid of some complaints.
3) Also, you reversed the drag and move, should be the other way around - when you click and drag it moves the wrong way, and it should use the left mouse button like most drag and move games.