Rav Shach mentioned that there are two factors that Torah success in Torah depend on: (1) Time and (2) the amount of energy put into it. But to combine that with the idea of the Rambam of learning Physics seems hard. If the Rambam would be a lone opinion in this it would be easy to dismiss him. But you find his opinion also in two important Musar books חובות הלבבות Obligations of the Heart and מעלות המדות [The greatness of Good Traits]
I think that one should divide the time of learning into Gemara, Mathematics and Physics. [The Metaphysics part I am not sure how to deal with.]
But I also want to mention that Torah must not be used to make money. So while learning Torah is important, using it to make money is a very terrible sin as you can see in Pirkei Avot.
