I'm not a Makarenko to draw up a complete structure, with proportion of each fields and the content of the school books.
I feel important part would be the integration of the student into their class, so there are no child who feel isolated and left out. This would create a friendlier group, and the students themselves can be involved in helping fellow students in learning - to give an example imagine a language class where the more proficient students each could lead a small group to practice the language together, while the teacher could focus on the least apt ones to help them catching up. Have to note that teachers are more "efficient" when teaching small group of kids (like really small, below 10), everything bigger just divides the attention too much, and even one kid with "behaviour problems" can render a whole class useless.
Another important part is tending the development of the body. So less sitting in class, more activities. If possible in nature too. Some physical activities allow theoretical learning too, think of Aristotle's peripatetic school where they were walking while he taught his students.
Curiosity has to be rewarded, just like taking initiative to learn new things. Mistakes - and acknowledging mistakes - should not be punished, but pointed out then giving the chance to to do better.
I'm not sure if Bernd is familiar with Waldorf/Steiner schools. In theory it helps with tard kids. But for example in kindergarten they literally punish those kids who ask questions. The educators only hum of the kids ask questions about the world and whatnot. They smother the children thirst for knowledge. This should not be done. If a child want to know they not just have to be given knowledge but put them as model example to follow for the other kids.
Now to tie up to the start, what to teach and what to skip... It would be nice if we could achieve that only a very little portion of the kids remained functional illiterate by the time of leaving primary school. Which is not the case today (so why even teach them anything if they can't even understand what they read???).