Panning / Zooming needs to have same precision controls as other features
I've seen some videos doing side-scrolling storytelling. As the video progresses, the canvas scrolls to the right. This is possible with the existing panning/zooming controls, but is tremendously difficult. The difficulty arises because you can't specify the X & Y coordinates and height & width of the window. Visually drawing the square makes it very hard for you to ensure that the start and the end windows are of the same dimensions. Panning/zooming should also allow you to draw a rectangle instead of forcing you to draw a square.