Add #6. Permanently expel disruptive students from public education.
Back in the old days of then good California disruptive students were removed from the regular high schools and sent to “night school” where they could earn a GD diploma (if they tried). This also included “shop” where they could learn automotive, carpentry, metal working, home econ, etc. I was in school there in the ‘50’s and 60’s. Also, girls who became pregnant were sent to “night school”.
Not just the students. Activist teachers are exponentially more disruptive.
A major part of the problem are the teachers themselves and, like all other public employees, who are notoriously difficult to eliminate.