(Also, if you have to write ancient mythology fan-fiction, please don't just rip off the Sumerians and claim it's original. I'm looking at you, Hebrews.)
On a tangential note, it seems that the author of that article is seriously confused about the chronology of the Ancient Near East. The earliest Sumerian cuneiform documents date from circa ~3100BC, and the earliest examples of Middle Eastern proto-writing are at most 300-400 years older than that. The literalist Biblical chronology used by the young Earth creationists places the date of the creation much earlier, around ~4000BC. So while creationism obviously has many problems, its alleged inconsistency with the Sumerian civilization is not one of them.
(On the other hand, there are extant examples of undeciphered proto-writing much older than 4000BC, most notably the Vinca,Tartaria, and Dispilio symbols, but none of these has anything to to with the Sumerians. However, the exact nature of these symbols, and how close they were to a real writing system, is unknown.)
From Encyclopedia Britannica:
...Sumer was first settled between 4500 and 4000 BC by a non-Semitic people who did not speak the Sumerian language. These people now are called proto-Euphrateans or Ubaidians, for the village Al-Ubaid, where their remains were first discovered. The Ubaidians were the first civilizing force in Sumer, draining the marshes for agriculture, developing trade, and establishing industries, including weaving, leatherwork, metalwork, masonry, and pottery. After the Ubaidian immigration to Mesopotamia, various Semitic peoples infiltrated
In this comment thread, I gave the following idea, on the topic of a method by which one might judge the Book of Mormon from a rationalist perspective:
I would appreciate feedback on this idea, for an admittedly selfish reason: I am trying to instigate in myself a Crisis of Faith. So, here are the questions I pose to you: