Total n00b - Qml beginner question set

[anda_skoa]

After reading a A Multilayered Architecture for Qt Quick I would like to make multilayer Qt Quick app as the article describes using Qml signals to pass data to c++ backend

Not a very good approach IMHO.
I think it is a lot better if the application C++ code does not know anything about QML managed elements.
Instead of passing a QML created object to C++ and connecting signals that might or might not be there, the C++ code should rather provide slots and functions that the QML created code can invoke.
That way you can easily restructure or replace the UI with the core knowing or caring.

Cheers,
_