Regarding the comma after the earth:
When in the Course of human events, it becomes necessary for one people to dissolve the political bands which have connected them with another, and to assume among the powers of the earth, the separate and equal station to which the Laws of Nature and of Nature's God entitle them, a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation.
As I can understand, there's no hard rules in English regarding use of punctuation marks, so one can put them simply anywhere if it makes the meaning of a sentence clearer. Yes?