Let's try to address your fundamental issues, then.zarguhl said:
The fixed term is an age thing. Basically, the reason for the length is that, aside from the material you have to work through (not to mention that the difficulty and complexity gets scaled up as you go along, plus time spent on vacation, plus time lost to reteaching what you've forgotten during vacations, and so on) there's just the fact that school is kind of like society's training wheels. There's a big difference in the maturity (in general) and learning ability of a 12 year old and a 15 year old.
I don't know about your school system, but when I was in school we learned economics in our senior year of high school, and our country's constitution in freshman year. Politics is difficult to teach, because no matter what you teach, somebody's parents are going to be upset. Plus, politics can change pretty quickly and from experience, it's really difficult to make last-minute changes to the curriculum. That said, in 7th grade (Philippine schools go from Grade 1-6, with some higher-end schools offering Grade 7, and then 4 years of high school) we had to memorize the names of the heads of every branch of government (Department of Education, Department of Transportation and Communication, etc.)
No good answer, other than "we're working on it". In an ideal world, every person would be educated and given the opportunity to live up to their potential. It's something all teachers want, and something that (I believe) governments want for their people. That being said, there are other things that get in the way: even assuming that education itself is free, you still have to get your kid to and from school, the kids still have to eat, and then there's materials (not necessarily books: even day to day things like pencils and intermediate pad). And aside from all that, there are some parents who just don't care. Where I live, there are some parents who don't bother sending their kids to school, they just spend all day drinking and smoking while their kids beg in the streets for the money that funds their parents' drinking and smoking.
If you are learning, then you are a student. Depending on your school, the exact meaning of a "good student" varies, but in general it's "follows rules", "gets good grades", and "occasionally does something that honor the school". And it's difficult to devote time to "knowing how to study". People are varied, and especially since Howard Gardner's multiple intelligence theory became popular in educational circles, there's the realization that teaching people how to study is like herding cats. Some people do fine with rote memorization, but others need to have music, or need to move around. Fact is, if you're trying to get good grades, you'll eventually find something that works for you.
Logic is taught in higher levels for a specific reason: until a certain age, it's difficult for a child's mind to understand anything abstract. You can't teach a kid about, say, the law of conservation of energy, because it's not something they can directly observe. It's why childrens' books need pictures: imaginative though they may be, children aren't able to interpret the abstract.
Also, on the matter of data evaluation, it's a 21st century skill. Some schools are only just starting to implement it, and as more schools focus on being "skills based" and not "knowledge based" like they are now, you're going to see a lot of schools teaching things like research and metacognition and self-evaluation.
Fun fact: Education is way better now than it was a hundred years ago. Most schools try to shy away from corporal punishment and rote memorization, and are going towards a more holistic, bottom-up model. The educational system I trained to work in focused on making a complete person, and not just drilling knowledge into kids. I assume that you didn't enjoy your own schooling, and for that, I apologize on behalf of all the teachers in the world. But calling the education system "the worst of all possible systems" is just outright wrong.