Where are the settings (e.g. for hotkeys and toolbar customizations) stored?

In Registry or file or folder?

Can I somehow export these settings into ONE file and re-import it on another Krita installation on my notebook?

Can I put all setting (files) into a subfolder (e.g. ".\mysettings") of Krita installation directory?

Peter

https://docs.krita.org/KritaFAQ#Where_a ... _stored.3F

I would recommend perusing the manual for further questions, it seems it is much faster for you to find answers to the many small questions you seem to have than to wait for us to answer.

I have searched the manual but didn't found a way to move the settings file (to the installation directory).

Is there really no way to keep all Krita files together?

Maybe through a command line parameter like:

krita.exe -settingfile=D:\tools\krita\kritarc

If the documentation is not clear to you, there are videos on youtube that can help you with your questions. But I would highly recommend the videos that are available here: https://krita.org/en/support-us/shop/. This way you can help support the Krita foundation by purchasing them.
However, the location of the directory you seek I am not sure of where it is on Windows, but on Linux it is in /home/username/.local/share/krita/. I would assume that it would be under your x64 program files \share\krita\ (something like that), but I haven't had to use windows in a while so I can not remember. It is where your presets and other resources are located as well. So maybe a search for adding presets might help you find that dir for windows.