Satan in his rebellion took a third of angels with him but the Bible doesn’t give us enough info as to the various dominions of fallen angels., demons, ect. Paul just gives a general admonition when he states “ For we do not wrestle against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this age,[a] against spiritual hosts of wickedness in the heavenly places”.
Christ noted that to cast out some demons, a time of fasting and prayer was needed(in the case of one pernicious demon that his disciples couldn’t cast out). There are lots of old church tradtions, various experiences of Christians and lots of fanciful writings that purport to further explain the various levels of evil entities...but the Bible lists very few and doesn’t explain the hierarchies. Christ speaks of the Spirit of antichrist which had already gone out into the world of which 1John 4 explains how to discern.
Now you speak of days of Noah as being as the days of the coming of the Son of man but that is a separate subject from whether or not it was fallen “pre Christians who fell further from grace who went off and married with the cainites” vs “rebellious angels” that ultimately brought on the wrath of God. Genesis 6 says that “It grieved God that he had made men and that he determined that his spirit would no longer strive with man after 120 years”
So it appears that God puts a lot of blame on mankind regardless of what any rebellious higher beings were doing. Paul says that “He that dwells in us is greater than he(Satan) that is in the world”. God could have helped pre-flood man if they had asked him, despite the fall from grace; Genesis did say(”after this time, men began calling upon the name of the Lord”). Enoch walked with God and so could anyone if they had wished.
I don’t gloss over anything in Genesis 6...but there is a danger in arguing over these things that we gloss over the love that the Father had for this world that he sent his only begotten Son! That is what we dare not gloss over! One can be a “sethite” or a “fallen angel” theorist when it comes to Genesis 6....but one had better not be a Jesus Christ denyer! As in the days of Noah, did not our Lord say that thus would it be in the day of the coming of the Son of man? So if we apply equivalence...are we not seeing increased world violence, blasphemies against God everywhere? We might even see the rise of very demonized humans up to and including the Beast and his false prophet...increased incidents of Nephilim and bizarre human mutations as well as many claiming to be Christ. If the days of the coming of the Son of Man are anything like the days of Noah....then hold onto your helmets of salvation because it is going to get really strange!
I don’t disagree with you on what is of primary importance. Really don’t disagree with you at all. Church tradition is one thing, but we see the use of Rephaim in Scripture. It is all a theory because the Bible is not explicit. However, when you put several passages together they start to tell a story. External sources also corroborate the story, but you can get it straight from Scripture, or at least key pieces of it.
In terms of Genesis 6 and blaming man, I think God blamed man for his part. But I also think he put the angels in chains in Tartarus. It was a very bad thing that transpired.
I don’t think we will see exactly the same thing today, but I do think some of the genetic manipulation and postulation we see in transhumanism is an attempt to reverse the curse and create man in man’s own image.
We certainly are in for seeing some strange things indeed.