They way people usually translate him in the religious world is that he meant something like mysticism even though he refers specifically to the physics and metaphysics of the ancient Greeks which clearly is not the same thing.
I have usually defended the Rambam's based on the idea of the hidden Torah that is concealed in the work of Creation which you do find in the Ari. But that does not mean the Rambam is referring to the Ari.
[The hidden holiness in creation is a fairly big subject mentioned by Reb Nachman.]
And even though I do hold the Rambam was right, I still feel the learning "Musar" the ethical works written during the Middle Ages is important in order to come to fear of God.--
Reb Nachman's own objections to what is called secular learning has to be understood as a reaction to the over-sided emphasis on on secular learning that the enlightenment had. Both the gentile enlightenment and later the Jewish one. As a reaction to that, Reb Nachman's ideas can be understood. Certainly the Enlightenment was not aiming towards fear of God of learning Torah.
My own emphasis of Physics and Metaphysics can also be seen in the light of my experiences in the religious world where I saw over religiosity does not bring to fear of God. Just the opposite. Over religiosity often comes with exaggerated degrees of wickedness as anyone in the religious world can bear witness to.
[Using Reb Nachman as a source and an authority seems to be an venerable Litvak practice. I never even heard of any Litvak gadol in Torah claim otherwise. Though there is an an awareness that Breslov is a cult, still people freely borrow and make use of the ideas of Reb Nachman pretty much all the time and I approve of that
The truth is my history with Reb Nachman is long. But the sum total of my observations is easy to sum up. People that become Breslov go downhill very fast. People that stay Litvak and simply learn Reb Nachman privately gain a lot. Nothing could be simpler.