Good points! The research and practical experience for many of these aspects is already there, though mostly only in the context of therapy, i.e. in cases where people already experience problems to a degree that it negatively affects their personal and/or professional lives.

What I mostly meant was similar to your stress example. Many people don't actually know what stress is, how it manifests, and most importantly, what you can do about it. Many also don't know that people can have very different thresholds of tolerable amounts of stress, and that those thresholds can siginificantly differ for the same person doing different kinds of work/studying etc. (e.g. some people have very low tolerances for arguing/discussions in work groups but can effortlessly dig themselves into research for 8 hours, others can do meeting marathons but have problems with physical work affecting their mood and so on).

In these cases many aspects of both the basic knowledge, ways of prevention and methods of coping with stress are well known, they just aren't taught in regular school. There is slow progress, though. In my country there often are e.g. social pedagogues in primary and secondary schools, helping with these kinds of things - though often only when they already manifest themselves as problematic behaviour.