Being a software developer myslef and at one time developing more UI than I do now, I am quite amazed at the simplicity (and the power) in the UI design.
I also share the concern of many of polluting the UI vs. all of us users wanting more and more. I have a couple of ideas that you may want to mull over
Right now, all of the tools that make marks reside on the tool wheel in the lower left hand corner. Obviously adding more mark making tools would go here. This could lead to a crowded, confusing looking tool wheel. Here are some suggestions:
1. Allow the user to put the tools they want in the available slots. I know that I use the brush but very rarely the airbrush. If I had this capability, I would not have the airbrush at my immediate disposal, but I would know that I could always access it via the menus.
2. Right now, only a quarter of the tool wheel is shown. Make the tool wheel a wheel that I can spin so that I can see the other parts of the wheel. Spinning the wheel would reveal other tools at my disposal.
3. A combination of 1 &2.
Thanks for listening.