Loading additional QML files

[anda_skoa]

(1) Am I using correct approach for dynamic loading of Items defined in *.QML file?

Your case looks much more like the use case of a Loader.

A general rule of thumb is that you do not attempt to access QML created objects by objectName and findChild/findChildren.
This kind of dependency inversion (C++ code depending on specific objects in QML) is almost always a bad idea.

(2) What could be the cause for the reference errors?

Maybe order of deletion gone wrong.
Try to not set JavaScriptOwnership, the QObject parent should be enough.

But again, this looks like a classic Loader scenario to me.

Cheers,
_