Thanks for that Neil. I tend to agree that 1 Enoch shows signs that many parts of its narrative elements are derived from Genesis, i.e. that they do not pre-date Genesis.
However, as I've stated in other threads, in reading Genesis there is still the sense that Genesis 2-11 is a redacted narrative. There is still the sense that Genesis 2-11 is not a complete story, but rather that it is a shorted version of some longer story. The problem is that there seems to be little indication that any such longer story was actually known.
Enoch literature seemed like it had the potential to record elements of creation narratives that pre-dated Genesis, and thus may contain elements of the longer story, but the more I look at it the more it simply looks derivative, as Alexander suggests.
To me, Genesis 5 looks largely like an insertion into the narrative that runs from 2-11, it seems to interrupt between 4 and 6.
But, interestingly, the writer may also have portrayed God as terrestrial.
21 Now Enoch lived sixty-five years, and fathered Methuselah. 22 Then Enoch walked with God three hundred years after he fathered Methuselah, and he fathered other sons and daughters. 23 So all the days of Enoch were 365 years. 24 Enoch walked with God; and he was not, for God took him.
This is typically read figuratively, but Genesis 3 describes the Lord God walking in the Garden and the "sons of God" from Genesis 6 who consort with women are surely meant to be terrestrial gods. So I would say that its possible the writer of Gen 5 meant to depict Enoch as literally walking with God.
This then ties into the way in which the Enoch literature reinterpreted Genesis. In Genesis the Lord is a terrestrial figure, and the divine beings live on earth prior to the flood, but in the Enoch literature God and all divine beings are always heavenly and were never terrestrial. In Genesis (and perhaps pre-Genesis stories) Enoch was with God - on earth. But when the writer of the Enoch literature moved all divine beings from earth to heaven, Enoch of course had to go up to heaven with them.
But perhaps there were pre-Genesis stories about Enoch learning from the Lord on earth, like being a student or apprentice of the Lord. But for whatever reason the writer of Genesis 5 didn't want to have Enoch passing on knowledge from the Lord.