[linsuman]

I know you asked only for grammAr (do not MAR your gramMAR) and punctuation, but if I may make an observation-for I had a difficult time reading this-you use a lot of emotionalism and no proof. Because of this, the paper sounds more like a rant than an essay. What is the purpose of your paper? Forgive me if I have misjudged because I did not know the purpose.
That said, before my mind gave up, I did find some things to recommend:
Sentence 1 lacks parallelism. "the land of the free," "the melting pot of the world" are parallel. "a country..." is not.
Everyone is singular. It needs to agree with its antecedent.
2-However,
Commas always go inside the last quotation mark.
3-How does one "ideally address" any issue?
Semicolons are used in a series of items if the items themselves contain commas.
Good luck.