Hey. Scratch needs to start adding shortcut keys to making a sprite, and you should be able to use the scroll wheel. Just like when you switch from the paint brush and the eraser or something like that. You could also do a shortcut key for zooming in and out.
Thanks
Offline
For your first idea, why, it's not hard to change from pen to eraser or zoom in and out using the mouse and it doesn't take a long time. For you second, it might be useful, but it's easy to work around (use lots of spaces or use different sprites) and I think that this should go in suggestions.
Offline