I'm a relative newcomer to Krita, and thought I would give some feedback both on what I like, and on why it's taken me something like three years or so to become even trivially proficient in Krita (tinkering a couple hours every month or so).

WHAT'S GOOD ABOUT KRITA:
- Way way faster than Gimp when working on a large canvas.
- I like the color picker over on the left with it's history. Really neat and fast to use.
- Mirror modes are good fun and useful in lots of cases.

QUESTIONS AND SUGGESTIONS:
The number of preset brushes: There are hundreds of preset brushes. And yet It's hard to find one that just draws normal lines! I would suggest having a favourites tag that is open by default with ten of the standard normal brushes (airbrush, simple paintbrush, simple pen, smudge and so on).

Everything is in categories: Want to change a layer or pen's color blend mode? Got to figure out what category it's in. As someone who already knows the names of what I want to do, being able to type would be amazing. This will just take learning I suppose, but maybe put some common blend modes (eg linear light, add, multiply, normal) into the "Favourites" by default?
Same thing in lots of places. Is "Color Adjustment Curves" in "Color" or "Adjust". Isn't everything an Adjustment anyway? And why is "Linear Light" in the "lighten" category. That's not really what it does.

Sliders at the top. Size and opacity by default. That's useful in many cases. It would be nice if it linked to what you had enabled in the pie right-click-menu for that tool, so you could put things like"Flow" up there as well for some brushes.

The place to create and to delete brushes is different. Be nice if you could delete brushes in the same dialog as creating them - so if you mistype a name you don't have to go hunting for the delete button later.

Layers and Brush Presets in the same place. These have to be the two most used dialogs, yet by default you can only have one or the other. As soon as I figured out how, I split them up. I put the preset brushes over on the left (with the other place where you chose what tool you're using).

Shortcut Key map under "Help". I really really like shortcut keys. But it's hard to learn them, It'd be great to create a non-modal popup under "Help -> Keyboard Shortcuts" so you could open it and put it next to Krita as a cheat sheet.

Hi,

You made some good points about tiding up some Ui elements and making Krita a bit more user friendly. But some of these are very easy to fix yourself pretty quickly:

The number of preset brushes:

As far as I know, the brush preset manager is currently under development that addresses these and other issues. For the moment, you need to manually choose these ten favorite presets and add them to a tag. You can easily create as many tags as you wish by going to the brush presets docker, and clicking tag. If you then right click on a preset, you get the option to add it to that or any other tag.

Everything is in categories:

I agree that the layer categories can be confusing and the fact that the modes are in alphabetical order does not help much either. But you just need to dedicate a couple of minutes and select the modes you wish to have readily at hand by going through the categories and ticking the little box to the left of these modes. You then have these blending modes at the top of the list, just like you would in Photoshop. And you only need to do this work once, because the favorite blending modes are saved in your configuration.

Sliders at the top

The sliders that you see in the toolbar can be changed, though not dynamically as you suggest. Just go to Settings > Configure Toolbars and add/remove any feature you like.

This might be what you are looking for "Sliders at the top" https://docs.krita.org/On_Canvas_Brush_Editor