I have no problem believing the earth & the universe are billions of years old. Woven into the Bible are hints of a time before time.
My point about the elevated sea beds has to do with radical changes that have happened to earth's topography, not that the elevated sea beds were formed during the flood.
The purpose of the flood is what is important, which was to wipe out the man/fallen angel hybrids.
"The purpose of the flood is what is important, which was to wipe out the man/fallen angel hybrids."
Well, maybe.
On the text, the purpose was to wipe out the evil.
You're assuming that angelic blood is particularly evil, but Cain didn't have any, and he was a murderer. Etc.
It's an interesting theory (on the text). Of course, after the Flood, the angels started doing it again. Exodus tells us about Nephilim in Canaan.
I think that "the Flood" is the racial memory of most of mankind of the surging of sea levels around the world at the end of the last ice age, when the glaciers melted and sea levels surged. (Blending this with Genesis literalism, the "Tree of Life" would be somewhere in the mire underneath the Persian Gulf now.) Those high seas were real, and devastating, and left a mark on the memory and legendarium of mankind, including the Mesopotamians, whose creation stories include the Flood, which stories the original tribes of Abrahamites took with them on their westward journeys.
The difficulty, for some, is accepting that Genesis is sacred myth, recounting a moral but not literal events, but the Gospels, much nearer in time, are real history.
Some have asserted that if Genesis is not literally true then the Gospels and Jesus' Resurrection aren't literally true either. This does not follow logically, although I understand the motive for it (it makes things clear and neat).