Each Command/Address type shortcut has a trigger and an action (command).

Keeping an overview is somewhat difficult because the shortcuts in the system settings are divided into three groups (Global, Standard and Custom) and the Global and Custom shortcuts are divided into about 17 subgroups.
In the worst case you have to manually search them all one after the other to find something you are not sure about it's location.

After all, "qdbus org.kde.kglobalaccel /component/kwin org.kde.kglobalaccel.Component.shortcutNames" displays a list of all names.

What's the best way to get ahead?
How can I retrieve the assigned shortcut and the associated command for each element of this list?

My wish would be a complete three-column table (shortcut name, trigger, action (command)), which you can sort and filter as needed - a CSV file would be enough.

Another idea was to evaluate the text file obtained by exporting the keyboard shortcuts. But its format is quite difficult, and above all this way the global and standard shortcuts remain unconsidered, although you may have assigned other shortcuts to them as well.

Anny suggestion how to complete and get the desired table?

I agree, sifting through KDE's shortcuts can be unnecessarily time-consuming.

Another variation from working in Intellij is to just have a top-level search bar which can match on any of name, trigger or action and highlights/presents matching locations.