We need an ERASER tool.

[Petri]

We just need it...
Brush and Eraser are the two most used tools in digital painting software... and when you are sketching, you usually want an eraser that is bigger than your current brush.

With this erase mode thing, it's always messy. A lot of artists go in quick sucession of stroke/erase, carving something. Changing the size of the eraser everytime completly breaks the workflow.
That's why people are still using photoshop.

krita has 2 big advantages on Photoshop right now... 1 - easily recoding the art process... 2- easily creating base colors with color mask fill (this one saves a lot of time)

if we get a better eraser, things will get a lot better.
People think the bursh engine is a big advantge, but most of the great artists rely on a very small pool of brushes, and use a lot of simple round and square brushes, without any effects or textures.

A better slider for brushsize with right click would also be nice, altough i never looked if there was some custom option for that. Right now the right click shows a big fancy pannel that is just too much, there is zoom, brushes, color pallet, brush setting, etc.... we don't need all of that. The thumbnail on brushes is also too much for long run, a simple shape of the brush would probably work way better.

[Ice Scream]

who is we? I have no idea what are you talking about.

[MadMinstrel]

You should continue learning Krita. The issues you mentioned already have solutions. It's not the solutions you're asking for, but they work.

For the eraser, one solution is to simply have a dedicated eraser brush. There's also an option in the settings that makes the size of the brushes in draw and eraser modes independent.

As for changing the brush size, just press the shift key and click-drag your mouse. That changes the brush size, no sliders required. Very fast and nice. Be sure to activate the brush preview option in the settings.

The right-click Pop-up Palette can be customised in the Settings as well if you feel it's too much.

When making your brush you can in fact paint a simple shape of the brush in the thumbnail. The built-in brushes are just extra-nice.