So a “root of bitterness” is not an attitude, but a person who is presumptuous and flatters themselves in their sin, one who hears the word of God but shrugs it off as inapplicable to him or herself.
Pastors and theologians tend to skip over the many references to giants in the Bible. However, Douglas Van Dorn tackles this subject head on in his book, Giants: Sons of the Gods.
According to modern critical scholars (in the academic sense) of a more liberal bent, the history of Israel as presented in the Old Testament is basically a fiction.
God explicitly forbade His people in the Old Testament from marrying Canaanites because they worshiped false gods, a practice that Yahweh knew would lead Israel astray.
In my experience of popular preaching and teaching, a vague impression is often conveyed, if not explicitly stated, that “son of man” is a way of emphasizing Jesus’ humanity, highlighting the fact that Jesus is a real flesh and blood human.