Fixing the Brush Engine, Selection Quality and Shortcuts

[Rocketdrive]

My main usecase is illustration, as such I am a little picky when it comes to the brush engine and paint related stuff 

I used Photo for almost a year for most of the digital illustrations I did. Long story short: I found it suberb for finishing touches and compositing, as well as areas that I could create as vector shapes. But for actual drawing I switched back to other tools. Now I have no desire to bash, but would rather like to point out some areas that could improve the drawing experience a lot.

• Brush engine. It needs to become more fluid, and natural. Jittering needs to be addressed. Apple has nailed it with Predictive touch and Apple Pencil, and every app that relies on both. Adobe has nailed it with Photoshop and Wacom. I'd love to see Photo get there, too. In fact, Photo and Designer on iPad are much better for drawing than their desktop counterparts.
• Keyboard shortcuts. I'd love to see more flexibility here, at the cost of a more complex setup. Temporary hotkeys would be great, i.e. a function is active only as long as the key is being pressed. Like, hold "r" while dragging the pen could rotate the canvas. Or hold "s" and drag to change the brush size. Also, I would really need every function, toggle and widget in the UI to be configurable.
• Selection quality. Selected areas always look (and are) slightly jagged. It's not a biggie, but selection quality could be better.