In short, the Noachide Laws provided the gentile nations with a moral code. The importance being that adherents to the law were regarded as righteous and assured a place in the world to come.

The Torah only requires Jews to follow the law of the Torah. According to Judaism non-Jews are obligated to follow just the 7 Noachide laws which are described at http://www.answers.com/topic/seven-laws-of-noah

Yes. Judaism encourages freedom of religion. Judaism is against proselyting and only reluctantly accepts converts, after making sure they have no ulterior motives. Judaism believes all of mankind should keep the seven Noachide laws, but otherwise can keep any religion they wish.

Noahide prophets are The Seven Laws of Noah (Hebrew: שבע מצוות בני נח‎ Sheva mitzvot B'nei Noach), often referred to as the Noahide Laws or Noachide Code, are a set of seven moral imperatives that, according to the Talmud, were given by God to Noah as a binding set of laws for all mankind.[1] According to Judaism any non-Jew who lives according to these laws is regarded as a Righteous Gentile and is assured of a place in the world to come (Olam Haba), the Jewish concept of heaven.[2] Adherents are often called "B'nei Noach" (Children of Noah) or "Noahides" and may often network in Jewish synagogues.

What riches? There are poor Jews, middle class Jews, upper class Jews, just like there are with ALL PEOPLE. Chosen people refers to being chosen to obey the 613 commandments of the Torah, like keeping kosher and observing the shabbat. Non-Jews have commandments too, and their own covenant with G-d. They are supposed to observe the Noachide laws.