The flood as depicted in Gen. 9-11 is not a problem if it is a description of a flooding of the then known ANE world, in other words a massive regional flood devastating that population. And in fact there are mud layers and other geological evidence in that region that something cataclysmic did happen thousands of years before Christ in that locale. The ANE writers are not making up a fairy tale in their various tales about a Noah figure, a boat, a survival of a massive flood. And there is also no reason to think that the genealogical Adam is a later byproduct of thinking about the Adam in the story in Gen. 2-5. All of that is part of the original story. 1 Chron. 1.1-3 and Luke 3.38 are just following Gen. 5.3-5’s lead. The writers of the Bible believe in a God who acts in space and time and is intimately involved in human history, especially in the lives of his people.