I agree with you on having a systematic base for children, there's also an argument to be made for the prison-aspect of schools where school keeps less well-off children off the streets and not starving. I don't think it should last until 18, though, and I really think it should be nothing more than a base. That means the "four" R's: reading, 'riting, 'rithmetic, and 'rogramming. (This relates to the other topic of HN: can every human regardless of IQ or other genetic factors learn at least the basics of each of these? My answer is currently no, but clearly some students we might want to place in the "no" category really just need more time/perspective than others.)

So here's a solution that builds from the free core competencies program. After competency is achieved in those, give them a free laptop which has access to free public wifi (which may for the Greater Good have certain things restricted (and anyone smart enough to get around the restrictions is probably smart enough we don't have to worry about them)) and can be recharged freely at various charging areas. (e.g. libraries.) Allow corporations to setup and finance trade schools for various professions, and let the market decide what programs people take. If corporation X is in the business of plumbing and needs more plumbing, they can offer incentives to take their plumbing program (lower fee compared to other programs, even zero fee or negative fee (paying to become a plumber), future contract-bound promises of a job, etc.). If corporation Y is in the business of basket weaving and decides they don't need any new workers in the near-or-distant future, they can just not fund any program for basket weavers and no one will spend time trying to become one only to find out later to their dismay that their skills aren't in demand. There's still a place for the classic university of research and discovery and intellectualism (not the modern university of partying and drug experimenting and "get the paper to get a non-minimum-wage job"), but freed from the burden of low-quality students they can operate with less funds and more output. Would this scale? Would it be better than current affairs?

I'm not sure where you arrive at forums collapsing under questions. What is StackOverflow? Would it collapse if it had an order of magnitude more questions? I also think students are more likely to ask questions when they're behind a computer than in a classroom based on my observations as a student from K-12 and college that students don't tend to ask many questions in class.

Your idea of improving parental responsibility of parents today is interesting and I could see forcing responsibility upon parents having a large effect in the near-term--we don't have time for generations. The viable methods of force are probably too unpalatable for most people unfortunately. Apart from mandatory education standards for the parent and spending time with children, breeding restrictions could also be put in place as well as making it harder to get divorced. Breeding restrictions are also easy to enforce because RISUG for men is quick and easy and lasts ~10 years. But I doubt the US government in its current form would ever do such a thing. One thing it could do that would help the people-who-shouldn't-be-having-kids problem is not letting children be seen as a tax credit / welfare check.