1) Why did God set down two seperate standards for Jews and non-Jews to follow?
Why not one standard for everyone?
Actually He did but because we have free will, most did not. There was I think about ten generations between Noah and Abram, and as usual people did as they saw fit. Abram who's grandfather spoke Hebrew (remember Babel) still taught some of these basic oral laws. Abram was a Gd fearer and merited his generations to be blessed. Generations later, they kept these oral laws, traditionally sent their sons (patriachs) to a Yeshivah by Shem (son of Noah) to learn the covenants and oral traditions. Fast forward time to Mt. Sanai, the Torah and oral laws were given to the Jewish people and the 70 nations. Because the Jewish people accepted the Torah without hesitation, and kept the oral traditions of their forefathers...they merited the priesthood and to be an example to all nations both Jew and non Jews. The separation between us Jew and non Jew is that Jews are priviledge to the Torah and are born into it. For the non Jew you are not obligated to perform certain mitzvots but it is a priviledge to do so.
And why are the obligations to these standards for the most part, hereditary?
Jewish people made that commitment "we will do, and we will follow" Moses came and told the people all the words of God. The people responded with one voice and said, 'All the words that God has spoken, we will do.' Moses wrote down all the words of God. He arose early in the morning and built an altar beneath the mountain, and also twelve pillars for the twelve tribes of Israel. He sent youths of the Sons of Israel and they offered burnt-offerings, and sacrificed oxen as peace offerings to God. Moses ... then took the Book of the Covenant and read it in the ears of the people. They said, 'All that God has spoken, we will do and we will hear.' (Exodus 24:3-7)