I think what you ideally want is physics emulation, but Krita isn’t designed that way; it’s a broad use painting application.
There are several different brush engines, and a huge amount of variables to combine; that enables the creation of things that don’t seem possible on the surface - you can see a couple of examples I demoed in this thread.
Because Krita isn’t physics based, when we create natural looking brushes we have limited scope for emulating behaviour, but can often achieve a convincing look. The watercolour brushes are a good example of this. Dry media such as charcoal are easier to emulate convincingly than more fluid media types.
We don’t currently have a colour pickup/dirty-brush option available, but I think that is being worked on by @Voronwe13. That will work by combining the clone brush with the existing engines i.e. pixel and colour-smudge.
Your best bet for dragging colour on the canvas currently is either the smear setting in the colour smudge engine, or using the clone-brush (as I did in the still-life fizzyflower linked to above). You could bake specular highlights into an RGBA brushtip, or use a lighting layer-effect.
I’m not sure displacement is currently possible - it might be with a g’mic filter, but I haven’t managed to do it myself.