Unlike you, I carefully distinguish between "spirits" (disembodied demons and hybrid human-elohim), the human spirit or soul "person", and the "spirit" that animates body and immaterial soul. Your views on this arise from a fundamental fallacy, "hasty generalization". Many words have more than one reference, and "spirit" is one of them. "Gas" is another. It could refer to gasoline, gas in the atmosphere, flatulence etc.
This is all wild speculation. Human has no spirit of its own, it's dust formed from ground, the what you call "human spirit" is the animating life-giving breath from God, what you call "immaterial soul" is the living STATUS of the body.
As for demonic spirits, they come and go at their own will, God didn't breathe any of them into anybody, and I've never implied so.
When an unclean spirit goes out of a man, he goes through dry places, seeking rest, and finds none. Then he says, ‘I will return to my house from which I came.’ And when he comes, he finds it empty, swept, and put in order. Then he goes and takes with him seven other spirits more wicked than himself, and they enter and dwell there; and the last state of that man is worse than the first. So shall it also be with this wicked generation. (Matt. 12:43-45)
Angels are corporeal, not spirits as this verse proves:
What kind of "angel"? This word in Greek simply means "messenger", which could be any being who is tasked to deliver a message from God, not necessarily must it be that mythical winged majestic creature. In John's vision, an angel equated himself with John and the prophets as a "fellow servant".
Then one of the seven angels who had the seven bowls filled with the seven last plagues came to me and talked with me ... (Rev. 21:9) Then he said to me, “See that you do not do that. For I am your fellow servant, and of your brethren the prophets, and of those who keep the words of this book. Worship God.” (Rev. 22:9)
Also, corporeal in what body? According to the bible, not me, or any doctrine, dictionary or philosophy, there're celestrial bodies suitable for heavenly abode, and it's different from terrestrial bodies.
There are also celestial bodies and terrestrial bodies; but the glory of the celestial is one, and the glory of the terrestrial is another. (1 Cor. 15:40)
Therefore, you're the one who's guilty of hasty generalization.