Also pressing space should be the hotkey for the picture mover.
That I disagree with. While its extra size is convient as a result of it the space-bar has the down side of extra springs to push against and a generally poor feel which makes any other key a better candidate IMHO (I hate games that use space for fire, or platformers that use it for jump). Customisability would satisfy both opinions for better goodness.
Do you use graphic programs?
Almost all of them do that and you get used to it pretty quick.
Hell, even simple oekaki programs have space=scrolling.
While I agree with you that space is not the best key to map jumping in a precision jumping game to (although it works just fine in any egoshooter) it's pretty much standard for scrolling in graphic programs.
If I wanna move the picture up, I keep space pressed and just drag that thing up. Nothing wrong with space here.
All hotkeys will be (when implemented) user-definable.
Another detail that might be worth mentioning would be that the previously used tool should be automatically selected once the scrolling-button is released so you would not have to press space *scroll* b *draw* space *scroll* b*draw* e*erase* etc. all the time.
I know it's canon and you're probably already doing it but if you don't, things become tedious.