A nice feature found in other image editing software is the "hand" to grab and pan the image around when it doesn't all fit on one screen (whether due to being zoomed in or not being zoomed out enough). A common shortcut to enable this panning feature is the spacebar. That is, while spacebar is held, clicking and dragging the image should "grab" it to pan it around. Once the spacebar is let go, your previously selected tool should be active again.
I would love to have this hold-spacebar-to-pan feature in SC, please!