I use Blender and I quite like it's Pie Menus.
you can even edit your own menus in blender if you know a bit of python
https://vimeo.com/103321600

this is all I need really for krita is another overmenu that I could assign to a hotkey:
i’m looking for is pressing a different key to pull up an over-menu (accurate terminology?) that has pulls up favorite brush sizes and quick brightness intensity icons
this would do the trick too.

1st solution I had in mind.
So I spend a lot time in fullscreen mode (tab).
and would like to adjust brush size and brightness with more precision/quickly
I kind of found a way to get this to work. i\’d like to just hover over size and use arrows keys on keyboard. hovering doesn\’t activate it though, you need to click then use arrow keys but even then sometimes it doesn\’t work.
pressing tab to adjust color brightness isn\t a big deal but would like it in this menu.

I made this picture to show what I would like:\

you could drag the middle bar to the right or left in increments of 10% all the way to 200% (twice the size of the base value) or to 0%.
each + – hit would add/substract 1%