Blessings Clee622,
I have noticed that you interpret scripture with scripture, which is the way we should be arriving at our conclusions. That said, and regarding the woman, below is the reason why the woman of Revelation 12 is representing Israel:
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"Then he had another dream, and he told it to his brothers. “Listen,” he said, “I had another dream, and this time the sun and moon and eleven stars were bowing down to me.”
When he told his father as well as his brothers, his father rebuked him and said, “What is this dream you had? Will your mother and I and your brothers actually come and bow down to the ground before you?”
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God used the same symbols in Joseph's dream to identify the woman of Revelation 12.
Sun = Jacob
Moon = Wife or wives
Eleven Stars = Eleven of the twelve tribes of Israel, with Joseph being number twelve
The woman clothed with the sun, with the moon under her feet and wearing a crown of twelves stars is representing Israel.
Though you are correct in that Satan caused a third of the angels to rebel in their original fall, the reference is to that event that will take place in the middle of the seven years, when that war takes place between Michael and his angels, who fight against Satan and his. Satan and his angels still currently have access to heaven. But when that war takes place, they will be cast out and restricted to the earth, which is the 7th trumpet and the 3rd woe.
"Therefore rejoice, you heavens and you who dwell in them! But woe to the earth and the sea, because the devil has gone down to you! He is filled with fury, because he knows that his time is short.”
That Satan knows that his time is short, is in referring to the fact that when he is cast out in the middle of that seven years, he then knows that there will be only 3 1/2 years before Christ returns to the earth to end the age, where at which time he is thrown into and restricted to the Abyss during the thousand years reign of Christ - Rev.20:1-3
I believe that I can help you understand the meaning of the flood that the dragon/Satan sends out after the woman. Please consider the following scriptures:
Floods, raging waters, torrents, Rivers, as symbolic representing armies:
"If the Lord had not been on our side—let Israel say—if the Lord had not been on our side when people attacked us, they would have swallowed us alive when their anger flared against us; the flood would have engulfed us, the torrent would have swept over us, the raging waters would have swept us away." - Psalms 124:1-6
"Reach down your hand from on high; deliver me and rescue me from the mighty waters, from the hands of foreigners whose mouths are full of lies, whose right hands are deceitful." - Psalms 144:7
"His sons will prepare for war and assemble a great army, which will sweep on like an irresistible flood and carry the battle as far as his fortress." - Dan.11:10
"At the time of the end the king of the South will engage him in battle, and the king of the North will storm out against him with chariots and cavalry and a great fleet of ships. He will invade many countries and sweep through them like a flood. " - Dan.11:40
"Who is this that rises like the Nile, like rivers of surging waters? Egypt rises like the Nile, like rivers of surging waters. She says, ‘I will rise and cover the earth; I will destroy cities and their people.’ Charge, you horses! Drive furiously, you charioteers!" - Jeramiah 46:7
"This is the word of the Lord that came to Jeremiah the prophet concerning the Philistines before Pharaoh attacked Gaza:
This is what the Lord says: “See how the waters are rising in the north; they will become an overflowing torrent. They will overflow the land and everything in it, the towns and those who live in them. The people will cry out; all who dwell in the land will wail at the sound of the hooves of galloping steeds, at the noise of enemy chariots and the rumble of their wheels. Parents will not turn to help their children; their hands will hang limp." - Jeramiah 47:1-3
Then from his mouth the serpent spewed water like a river, to overtake the woman and sweep her away with the torrent. But the earth helped the woman by opening its mouth and swallowing the river that the dragon had spewed out of his mouth." - Rev.12:15-16
As you can see, scripture over and over again, uses attacking armies or attacking people symbolically as torrents, raging waters, floods, etc.
That said, it should now be clear as to what the dragon/Satan is spewing out of his mouth after the woman/Israel.
I hope that this was beneficial to you