Paul, I'd first suggest that you read Egan's article that I linked to, as it shows the conflict between these three goals better than I can.

My own experience in watching our children go though school is that the first 6 years or so are quite effective at learning the basics. After that, school has a tendency to beat their brains into submission, or at least remove their passion for learning, IMO.

If I had to quickly redesign public education, I would keep elementary school and replace high school with something more resembling the Quebec CEGEP system.