You're right, I can't get attack move to work either. It was working last patch, but barely, was a pretty rough early implementation of it.
Try drag scroll instead of push scroll, if you hold MMB down while dragging the mouse it'll move the camera around really fast based on where the cursor moves. This way you can kinda flick your wrist to move the camera because you don't have to move to a side of the screen, in addition to it just being way faster than push scroll. One patch a few months back push scroll broke for me, so I fell back on drag scroll, now when RTS games don't have it I get annoyed. It is perfect for nudging the camera short-medium distances very fast.