Hi Günter,
1)"(If you haven't already, install and set up ArcGIS Runtime SDK for Qt, ...) ...which includes adding the references to the needed libraries."
Anwser: EsriRuntimeQt is part of the dependencies needed. Since this is a Qt SDK, you might need to include other Qt dlls for your application to work.
2) "In the Project References notice that the ESRI.ArcGIS.Client and ESRI.ArcGIS.Client.Local libraries are present."
Anwser: The following is a typo in our doc and it will be removed. Sorry for the confusion that it might have caused you.
Let me know if you have any other questions.
Regards,