Regarding the crescendo/descrendo tool, I agree that it's more natural to drag from left to right, so if they are separate tools, that would seem simpler to me.
Though I would happily accept that you might have to drag backwards if you combined both tools (buttons) into one, and had to drag backwards to get a decrescendo. There would still have to be a minimum size, but it would flip directions if you move more than a few pixels to the left.
Though I would happily accept that you might have to drag backwards if you combined both tools (buttons) into one, and had to drag backwards to get a decrescendo. There would still have to be a minimum size, but it would flip directions if you move more than a few pixels to the left.