When it comes to the Nimrod and Gilgamesh similarities, I think the biblical Nimrod is a character made up by the "Jews" of back then to demonize Gilgamesh, the semi-divine King who challenged the gods.

I myself don't believe the Bible events are really all that accurate. The Sumerian writtings are way older than the Jewish ones and the Jewish texts obviously borrowed a lot of their mythology from the Ancient Sumerians. So I believe the Sumerian version of the events is more accurate.

As for the new testament, I think the Jesus character is a deification and/or a mythological figure based on Julius Caesar.

So overall, I have a low opinion about the historical accuracy of the Bible. I myself am an agnostic. I believe that there are supernatural forces out there but I don't believe the things the Bible or most institutions teach people is accurate. I'm sure some of these beings are both good and evil.

I believe Enkidu and Gilgamesh were real Demi-God-like beings. That's why I'm interested in the Ancient Sumerians. I'm convinced me and a friend of mine are the reincarnations of Enkidu and Gilgamesh respectively.

One thing that isn't mentioned in the story is Gilgamesh's realization. Back when the snake stole the herb, a lot of people take it as Gilgamesh simply giving up on trying to beat death and try his best as a King in order to deal with it. But that isn't quite accurate. Back then, he simply realized that he didn't need the complete "undying body" immortality since it took a lot of his value as a human, and that he could continue to live on being reborn and protecting mankind.

The Nimrod character himself has been associated with snakes often, that's also part of the reason why I think he was made in Gilgamesh's image. The snake is a symbol/metaphor for Gilgamesh's powers of reincarnation.

The reason why he was granted the power of reincarnation and to be able to remember his past lives is because he has a role as the guardian of humanity. He is permanently the King/Ruler of the world. I suppose my or Enkidu's role is to be his foil/rival.