You vastly underestimate how much money it would take to do (3) alone, let alone anything else on here. Your assumption around the usage of educator hours is incorrect. I suppose it's worth seeing how you believe educator hours are currently used?
That said, I roughly assumed a private tutor cost of $50/hour, 5 hours a week, for 36 weeks per year. That alone would come out to $9000, hence the 'small group' suggestion- if each tutor is working with on average 3 students at once, it's a bit more tractable.
I'm not sure what assumption you think I'm making about current educator hours- the proposal is for a radically different usage.
My point is that you would need a lot more educator hours. There's no way to organize the current amount of hours in which you have "small groups" for 5 hours a day, unless small is 30 students per one teacher, in which case we're already doing that.
It's also not worth comparing tutor hourly wages to teachers as teachers have to deal with other things outside of teaching: calling parents, administrative tasks, behavioral issues, etc.
Also, it's worth mentioning that most of the things you've mentioned have been attempted at one point or another. There are a lot of constraints, interestingly money is not necessarily the main one depending on the issue.
The proposal was 5 hours a week not 5 hours a day, IIUC. Likely you'd still be looking at rather large small groups and/or a substantial increase in teacher-hours per pupil, though.
Part of the issue here may be that I found the education system to have net negative impact on my... education. The main value I see in the current system is providing child care, safety, and food security. If there is solid research showing that ~40 hours of the current approach outperforms ~5 hours of a tutoring-style approach in the general population, that would be evidence against my proposal. And that might exist, I just haven't seen it, since this is not exactly a formally vetted idea.
It's not designed to optimise for educational effectiveness.