signals and slots qt
Chapter 6: Signals and Slots | Cross-Platform Development with Qt 6 and Modern C++
Chapter 6: Signals and Slots. A chapter from Cross-Platform Development with Qt 6 and Modern C++ by Nibedit Dey
How Qt Signals and Slots Work - Part 2 - Qt5 New Syntax
Qt Designer also allows you to preview your GUIs using different styles and resolutions, connect signals and slots, create menus and toolbars, and more.
Signals and Slots - Qt for Python - doc.qt.io
There was a blog post written a while back called 20 ways to debug Qt signals and slots It addresses I think #1 and #3 of your questions.