You may not realizing that you are assuming anything, but you in fact are assuming things about the passages you are talking about. Satan is not even mentioned in the Genesis 3 passage, it's not until later that Satan is connected to the serpent, after the idea of the devil is introduced into Judeo-Christian, but mostly Christian, thinking. Furthermore, the curse to the serpent in Genesis 3:14 clearly is reflecting only the serpent itself, and whatever spirit is possessing the serpent. The curse upon the serpent also reflects the common near-Eastern belief that snakes ate dirt, referenced in Isaiah 65 and Micah 7.
The only assumption I made is that you generally believe in the words of Christ and Paul. I've argued with Christians in the past saying that the serpent in the garden and Lucifer/the morning star are different entities, neither of which is Satan, but I was shown that the New Testament does refer to the serpent in the garden as Satan (although I don't remember where I saw it).
In other words, there's no reason to indicate from what is said in Genesis 3, which is an allegorical and symbolic story, that Satan is involved in this story in any way whatsoever, the first mention of "Ha-Satan" is in Numbers. I think that it can be logically inferred that the serpent was indeed possessed or somehow under the control of Satan, and therefore Satan's punishment would be a continual lowering from Heaven.
I do not think that your liberal theology is buoyant. Recall that it was through one man that sin entered the world, and through one man that it was defeated. Now you are changing that reading to, "It was through one man who didn't actually exist that sin entered the world, and through one man who did actually exist that it was defeated." I do not think this was Paul's meaning, and it seems to be essential doctrine.
1) It will be both physical and spiritual, therefore eternal and of Heaven instead of Earth. (1 Corinthians 15:42-58)
I do not know what this means, and if you cannot explain it to me then you don't know either.
2) They will not suffer from sickness or death (numerous passages)
3) It will be like the resurrected body of Christ (1 John 3:2, Philippians 3:21)
4) While it will have physical form and solidity to the touch, we will have the ability to "teleport" (John 20, Luke 24:39)
5) We will still eat and enjoy food, but obviously will not be necessary (Luke 24:40-43)
Again, I don't know what it is about this set of properties you think is so different from angelic beings.
1.) Angelic beings certainly seem to be both physical and spiritual, and certainly seem to be eternal and of Heaven instead of Earth.
2.) Angelic beings do not suffer from sickness or death.
3.) Angelic beings are like the resurrected body of Christ. Recall in Matthew the guards collapsed in terror upon the countenance of the angels, so clearly they are quite glorified.
4.) Angels have physical form and solidity to the touch, as shown by the fact that men wanted to know them carnally. Also, they are clearly able to teleport.
5.) Angelic beings are not known to eat food, as far as I know, but there is no reason to suggest that they cannot do so and they certainly have no need of it.
So again, you've not shown me any distinguishable difference between former humans and angels. As far as I can see, the only difference will be their past experiences, but their current states will be more or less the same. Angelic beings are known to have been exiled from heaven, and there is no indication that this cannot occur again. Therefore there is no indication that former humans in heaven might not be exiled.
The Second Coming is not a scientific or historical event, but it is currently a theological concept, which is why I do expect you to accept the claims of theologians if you want to actually understand what Christians should believe about the second coming of Christ. The same goes for the doctrine of salvation, it's a theological concept, so the experts on it are going to be theologians. I am aware that people don't rise from the dead, teleport, fly, etc....and that's why it's a big deal that Jesus did.
I was raised in the belief that the apocalypse will be literal and physically real, and that it will occur any day now. If you think that's wrong, you're welcome to engage your friends on that. I don't really care, nor is it pertinent to the issue here.
And again, you've just asserted what you already did, so I'll do the same:
If your claims don't come from Scripture or if they aren't at the very least logically inferred, then your claims are fan fiction. You cannot whimsically dismiss claims from scientists or historians while at the same time expecting me to accept the claims of theologians.