Let me see if I have everything you have said put together correctly.
- Homo Sapiens evolved as normally understood.
- Image Bearers came into being with A&E
- This group of Image Bearers remained apart from the non-IB.
- For Noah, him and his family were whisked off to another universe where they experienced a year long global flood complete with whatever miracles were necessary to keep the animals and people alive on a wooden ship for a year.
- After the flood they returned to this universe and all of the living non-IB were transformed into IBs.
Is that about right?
A few questions.
Did Cain marry another IB or a non-IB?
Did the IBs not included with Noah die in this universe or the alternate universe?
Is there any archaeological evidence that the population in Sumer was suddenly replaced by a different population about 3500 years ago? Given the replacements came from outside Sumer I would assume there would be cultural differences that should be apparent in the archaeological evidence.
I will say your solution is, in the words of an old ad, two, two floods in one. You get the effect of a regional flood and the experience of a global flood. Both of which leave absolutely no trace that they actually happened.