This seems to me to be a field fraught with landmines. I would go slow and allow Holy Spirit to guide me into the truth. Having said that, I'll try and answer these 8 questions to the best of my ability, belief and understanding.
1. No.
2. Yes.
3. They came from Adam.
4. I wouldn't say so, but since the Lord hasn't revealed this to me, I can't say. But possibly.
5. No.
6. I do not believe so, though I have my suspicions about Nimrod, son of Cush, son of Ham.
7. Yes.
8. Yes, I believe so. "As it was in the days of Noah, so will it be at the coming of the Son Of Man." Matthew 24:37
Note: I use canonical and non-canonical sources for the following information.
I believe there have been numerous incursions on Earth by fallen angels, including one by Prince Sataniel and 2 of his cohorts. I need to do more research on this, though I believe these beings are found in the extra-canonical book of 2nd Enoch. - Genesis 6 talks about the bene ha-'elohim, a.k.a., the sons of God. I catagorically reject the silly attempt to replace the watchers with the good sons of Seth and wicked daughters of Cain. Such nonsense, in my opinion. Besides, why do we listen to a Roman Emperor and a pope? Not to say anything about a recent pope who wanted to baptize demons, though he called them aliens. Whenever this phrase is used in the O.T., it is referring to angels. The KJV translates the beings in Genesis 6:4 as giants, though I believe this was an error made by the KJV translators. I'll get into that another time. I prefer most other translations in this instance, which translate it as nephilim. "All giants are nephilim, but not all nephilim are giants." The dead spirits of the nephilim are what we call demons. When God tossed the watchers and demons into the abyss, He allowed 10% of the demons to remain on the Earth. This brings to mind the N.T. parable about the man who, after being forgiven of a great debt, refused to forgive a fellow servant of a small debt. The King ordered the jailer to throw the unforgiver into jail, where he was tortured. I believe that in real life, the torturers are demons. I recall a time when I refused to forgive someone and it sure seemed like I was being tortured. When I finally forgave, it was like the demon left me. Just what I believe. - I will now step on even shakier ground. Be fearless. Once as I was watching a U.F.O. video taken after dark, the videographer switched to night vision. The U.F.O. became what I call a small, grey demon. So it is my contention that so-called aliens are no more than evil spirits. As far as what they call, "alien abductions," I know they are demons and "angels of light," who are the guilty culprits. They leave when the name Jesus is called upon. "Ancient Aliens" dogma is built upon the theory of evolution. "Evolution is science fiction." This, I believe, is the basis for the last days' deception. Which I believe we are presently in. The darkness is getting darker, but the Light is getting brighter. For those up in arms over my writing, did you know that God will sometimes offend our minds in order to reveal our hearts? Look, I've spent almost every day of the last 8 years, under the guidance of Holy Spirit, scouring the internet and let me tell you, it's just amazing what I have found. - 20 years ago, I chose to follow Jesus by denying self and taking up my cross daily. This is how we mature. I die in Christ so He can live in me. I'm not asking to be believed just because, but I am asking that you think for yourself and look into it for yourself. With His help, you can do it. And I'm not saying to not listen to your leaders, who are a blessing from God. But what if he or she makes a mistake? We all do it. How will you know? It's not really about what translation you read, but how you interpret it. Ask God for discernment and a love of the truth. I did. Anyways, don't take my word for anything, instead, do your own research. The hour is getting late. Shalom and good night.