I am a simple bachelor student and i dont know much about Focault, but given that he is an important figure that has been influenced by and is a point of reference of many known philosophers, i think deeper insight into his way of thinking and reasoning could help you a long way in developing your own critical thoughts, as he would also help you understand lots of other 20 and 21 Century Philosophy.

There are many, e.g Foucault, Habermas, Freire. Look at carious Philosophy Department Modules on Critical Thinking

Foucault's archaeology of ideas is essential for any modern thinker. That ideas have their own clear history with connections to specific cultures or cultural events is itself an essential idea and once understood prevents absolutism and professional authoritarianism. Another reason why Foucault was loathed by psychiatry.