Lots of talk about files and iTunes but no specifics. What is this notebook exactly? Windows version? iTunes for Windows or Apple Music for Windows app? It all matters.
If you are playing purchased and downloaded material in iTunes, I’d use the iTunes remote app on a Smart device for music selection. The Smart device will be just that, a remote controller. The notebook will Airplay music directly to the selected device.
However, if using the Apple music app to stream music that has been added to your library but has not actually been downloaded, you will be at the mercy of your current internet speeds for quality. In this case as well, the Smart device with the iTunes Remote app is just that, and music is sent directly to the selected device from the notebook.
I wouldn’t be concerned with a wired connection vs Airplay to the NAD for iTunes or Apple Music. While the NAD supports hi-res, unless it received a firmware update, it does not support hi-res ALAC. Many new AVRs have 24/96 limits for ALAC over network and USB connections and the coaxial and optical ports on many new AVRs have 24/96 limits altogether. Apple added hi-res and then made it extremely difficult to transmit from one device to another for no good reason.