That’s great! It’s definitely a fascinating book. I see it as a collection of historical stories that can be a bit disjointed. The narrative emphasizes the spiritual aspects of the history, as well as the people and their stories, so that’s the part of the history you get. Genesis emphasizes creation, fall and then God’s covenant with Abraham. Are you familiar with theophanies or did you notice those?
Here’s my take on the Nephilim. Nephilim and Genetics But there’s many other threads here about them if you want to do a search. It’s a subject that’s never really been settled throughout Jewish and church history.