I would agree in part that most of the Meteorology theory can be deduced from first principles. I have found that a lot can be explained from the movement of the ITCZ alone, especially Global and area climatology, and winds for that matter. As for feedback, i would say with certainty that it is essential. Knowing the theory is great until you see the questions. The guys writing the questions take great pleasure in trying to catch us out. So being able to understand what it is they want to know if half the answer!!