I think what you found in the first part of Genesis is very interesting! You are so right, though! Pluralism is very apparent all throughout these first 11 chapters. Even though God created people differently, He desires a relationship with all of them. And the fact that he chose Abraham doesn’t mean he was trying to leave the rest of world out from a relationship with Him. In fact, the opposite is true; God was building up the people of Israel in order to reach the world through them.
Great job on your post!