I would suggest to add Pie Menus like this:
The benefit would be that you can easily access different tools/brushes or adjustmentoperation with just one short cut and a swipe gesture.
There is also not a single programm in the 2D Painting area which I'm aware of that has this feature implemented. This would make Paintstorm from the workflow standpoint pretty unique.
[Suggestion] Pie Menus
Re: [Suggestion] Pie Menus
You can use Custom1 panel and "Move custom1 Panel to cursor" hotkey