All very good points. Almost every one I practiced in my last 2 jobs, and was regarded as a good manager and leader. Companies don’t seem to be buying into it. Being a manager who is recently on the market again, almost every company (10 so far) wants a hands-on manager. Someone who will/can code. Questions about leadership are very sparse and textbook. It’s a regrettable state of things.
Some of your points are defined, documented theories: #2 Emotional Intelligence, #3 Situational Leadership, #4 9-box review model, #6 limit is about 8 for anyone, #7 Who’s got the Monkey?, #9 Team Maturity Models, #10 Four stages of competence, #11 Positive Intelligence. I no longer bring these up in interviews. I can see their eyes glazing over.
Your list is what managers really need to be, not always aligned with what is wanted.