More in-depth analyses can not raise your score, and more complications can not make your essay more advanced. Let's go through some of your sentences.
"Possessing curiosity and seeking novelty eternally, primary school students are supposed to have a higher competence in learning a foreign language than children at secondary school."
The modifier "possessing curiosity and seeking novelty eternally" seemed to be wordy and can make the sentence longer than necessary. In addition, it did not make sense to compare primary school students with children at secondary school since they might be seen as two entities. I would suggest another version, and I think it is somewhat easier:
"With curiosity, primary school students are supposed to have a higher competence in learning a foreign language than those at secondary school."
This can also be seen at: "On the basis of the foregoing, I punctuate that primary schools focus on encouraging foreign language exposure possible by creating an entertaining environment for them, a method which, in my point of view, should reduce pressure on primary school students."
This sentence took many lines of words, and there must be a reason to shorten it. By the way, what did "I punctuate that" mean? Moreover, there is an issue here. "a method which,..students" worked as a modifier, but what was it modifying? encouraging foreign language exposure? or, creating an entertaining environment? because both could somehow reduce pressure on primary school students.
Another: "According to language experts: ‘The brain of a 3-year-old child works twice as fast as an adult brain."
This sentence left many things to question. Did they carry out any scientific research? How large was the sample? Were there any scientific theories applied? What was the figure for the reverse?... It seemed that you were referring to part of a study while leaving it underdeveloped in your essay. You can give the statement as if it is your idea and then show your own explanations.
Last, "One of the reasons, children’s hyperactivity causes poor concentration that decreasing the theoretical capability."
"One of the reasons" and "decreasing" did not work here, and "the theoretical capability" made no sense. You have to rethink the sentence.