I think the point you make about physical actions causing a reaction to the spiritual is not that simple. If in rejecting God, our spirit is left in a void and becomes confused, some think this is the ultimate sin. Can the spiritual side be restored then becomes a default position. Re-incarnation declares it moves on to the next chance in another life. The belief in demons, states the spirit can join in demonic activity. I’m sure there are a host of other beliefs.
How people in the past viewed it was God keeping a record in a book. This tends to paint our spirit as just a data gatherer, or angel that reports back to God. Your idea that the spirit has a beginning and grows is not that much different than a collection of data entries into a book. I guess in modern times a direct computer interface to a computer collecting data would not be too different. I guess it depends on how much “body” one wants to make this out to be. I think God created humans in a singular act, and they immediately had this spirit connection with God. Communication was immediate and two way. I guess humans were allowed their own thoughts and actions, and “down” time. As pointed out putting too much physical framework into the spiritual can lead to way too much speculation.
So going too far, in expecting the physical to over effect the spiritual may be the wrong way to view the spiritual connection. It seems more simple to just view it as a collection of facts about our lives. Now God has seemed to allow some humans more sway over what happens in the spiritual side of things. But I do not see God as being a control freak, nor reacting or over reacting like physical minded humans would do. Before the Flood it seemed there was a struggle in this direct relationship. I think Adam’s descendants including Noah and all of us after the Flood did loose the original connection with God. But describing it as a physical phenomenon does not work, because the connection is not physical but spiritual. Some point in a human’s fetal development the connection is placed there. The age when humans are aware of this connection differs for all, but after that awareness the choices they make become their own responsibility in maintaining that spiritual connection. It is not God’s responsibility. I think the function of God’s Holy Spirit is to let God restore the link like it was for Adam and the original humans. I think the physical may perceive this as a very huge burden and responsibility. We do not worship God only by choice. Upon full revelation of God, I think we loose all choice in the matter. That is why God declares that in God’s presence the physical is completely dead. It is too overwhelming and powerful. The Universalist will then step in and say eternal life is not up to us, that in essence all will be forced by God’s love to embrace God. Because the physical is not inclined to embrace God, only the spiritual. But the spiritual cannot act on it’s own behalf. The spiritual is still controlled by one’s own ability to choose.
What Adam did, allowed us NOT to be universalist, but to think and reason on our own accord. Universalist make the error, that the physical is naturally drawn to God. Now we have evolution giving us a reason that God via Adam gave us a connection to God. This is as far from the truth one can get, and negates totally what it is to be a son of God. Adam was a created being all on his own right to think and decide along with all other humans beings created with Adam on the 6th day. They were universalist in the utimate sense of what it means to be one. Not so after the Flood. Humans have to seek God out and not through their spiritual connection, because it is “broken” meaning it does not work the way it did before Adam disobeyed God. The only way to fully connect with God is to submit fully to the Holy Spirit. To accept eternal life is to accept the obedience of Jesus Christ as God dying and coming back to life. To live a life pleasing to God is not being selfish at all, but technically is not universalism as we think it is. Because the physical in and of itself, cannot be unselfish. There will always be one thing that God ask us to do that we cannot do, because it goes against our own physical makup. This has nothing to do with any objective laws or standards. Jesus is the only objective standard in God’s eyes when it comes to a physical standard. So what God demands is not one size fits all. It is either accepting what God offered in Jesus Christ and not our own physical ability or it is giving up that one thing that seems impossible for us to do. Does that put God’s demand to us as an impossibility? No, not necessarily. It depends on how possible the demand is and how far you want to take the universalist postion. If accepting Jesus is the only impossible thing one can hold as in the only choice they have left to obey God in, that may be the only point one is ultimately past a possible choice. I think the easiest choice is to just accept God’s plan, and avoid trying to figure out any physical choices that God is demanding of us. That would involve giving up the universalist view of life. On one hand God’s plan cannot be the only way, but on the other, it kinda is.
PS. If I am not fully representing what universalist hold, it is not deliberate. It is the general understanding that all humans will be brought back to God as in the beginning. As some point out the future is not set in stone, but basing a belief on speculation of a future event gives us absolutely zero information. At one point in the past humans had no choice but to be connected to and part of God’s spiritual existence. Imo, it was because the full experience of God is overwhelming and only from the physical does not seem practical. That is why God set it up for one man to be the deciding factor. I am sure there was more pressure involved than just trying to please Eve, whom Adam blamed. If we think that all humans at that time had a universal choice in the matter, it does not make sense to still give humans a choice not to become like Adam. There would not be a distinction between humans who are sons of God and who are not. Now we have been told that sons of God are just angelic beings. It removes humans from ever being responsible for their own condition. It is quite possible that we would have gods walking amoung us and constantly reminding us of our fallen condition even today. That would seem to cause even more resentment towards God, not less. The Jews seemed to hate Jesus so much they wanted him out of their lives, not hanging around showing off and constantly condemning them. Is that what Jesus did, or was it a false perception projected onto Jesus? But not even the sons of God could handle the burden of living a complete spiritual connection with God in the physical. In the end, universalist seem to want everyone willing to join God, but yet there will be those who are not forced to.