A local flood wouldn't require the saving of any animals. Since they would migrate in from non-flooded areas. The story makes absolutely no sense if it's just a local flood. Given the many years it took to build the ark, Noal would have just moved to another area if it were just a local flood.
You ignore too many verses. Why, to be accepted by non-believers?
Concerning why so many different ancient cultures have flood stories, well that's easy: floods happen! Every region certainly has a "Great Flood" once every few centuries or so.