Having read through this extensive discussion, I have a few things to say that can help.
1) The YouTube channel: Domain of Science has an excellent Map of Physics that is hard to beat and perhaps would give students that sense of understanding that you are trying to bring to your class something you might use as a starting point and elaborate more on:
2) Most textbooks and places like Khan Academy follow a prescribed path through physics that mirrors in some ways the map in #1. Your students will look to these sources in order make sense of what they are learning so we don't want to add unnecessary levels of abstraction on top of it.
For non Calculus students there's this online resource:
https://openstax.org/details/books/college-physics
and for students versed in Calculus there's this resource:
https://openstax.org/details/books/university-physics-volume-1
Another resource is Ben Crowell's excellent books:
http://www.lightandmatter.com/
My suggestion is to incorporate references to these books for your students use doing it for each topic you cover.
3) As a physics major in high school and college, I was caught in the web of trying to resolve the physics popularizations of the day with all the magic and mystery presented with what I was actually learning. It caused me great confusion. The refrain from my teachers was always go back to the math, the math describes the physics accurately in ways the popularized conceptual ideas can't.
@phinds always brings this up in his posts about the balloon analogy of the universe or the rubber sheet description of how gravity works in relatvity. They get an idea across but you then have to drop the analogy before it derails your thinking ie don't read too much into the analogy go back to the math.
4) Have you ever taken math classes where the prof starts at a very general conceptual and abstract approach and its only in the closing days of the class that you discover how everything really fits together in a practical sense? I hated those classes, I would panic and question why I was learning something I didn't understand.
Your students won't have that confidence to stay the course and will panic because high schoolers are worried about their grade point averages and getting into the college of their dreams. So as teachers we don't want to use them as a testbed of new bold conceptual ideas when the focus of the course is to teach them physics as precisely as we can.
Your students will also panic over formulas to be remembered and when they are applied. Many will try to pick the formula needed based solely on the constraints and forget about the added clues found in the geometry and symmetry of the problem because that's what worked in other courses. I have x and y and this formula uses x and y so now I can find z... but wait now what? Typically when doing a force diagram, I would forget to add a force like tension and consequently got stuck.
