3. What was the spiritual state of those humans in the rest of the world prior to the Fall?
Still struggling with that one... Ideas would be appreciated. According to Romans 5:12 mankind had not experienced sin prior to the Fall, but Genesis 3 gives us some additional insight. The tree in question was not "The Tree of the Knowledge of Evil" the tree was the "Tree of the Knowledge of Good and Evil". Evidently mankind prior to the Fall did not know either good or evil... Still trying to understand what that even means.
It is a question that all evolutionary creationists struggle with.
According to some, A&E were the first humans to receive a spirit, when they went out into the world, their decedents interbreed with those other humans and their children were given spirits and so forth.
Others simply see them as the first ones to be born with a spirit and that eventually all humans got one.
Another one is that Adam and Eve were the first fully human and spiritual beings, God offered them a place in paradise, a place that IF they remained worthy, would be offered to ALL humans.
They failed and as such all humans suffered.
In short there are a few views that try and reconcile A&E with the rest of humanity.
4. What happened to humans in the rest of the world at the time of the Fall?
Struggling with this one too... According to Genesis 3:7 after Adam and Eve sinned their "eyes were opened" to know good and evil. Would this "eye opening" experience have extended to all humans across the globe at the same time? Don't know
Some argue that, like a virus, evil spread to all humanity from A&E and their off spring.
Others suggest that it was only A&E whose eyes were open and the rest of humanity already know good and evil.
5. Original Sin.
This one's a doozie! Scripture teaches us that all humans have an inherent tendency to sin, and observations of any person or persons for any length of time validates this Scriptural teaching. Is this inherent tendency to sin in humans a result of the Fall or did it predate the Fall possibly as a natural function of human free will and actually contribute to the Fall? One note here... I definitely draw a distinction between an inherent tendency to sin and consciously sinning. An infant has the inherent tendency to sin, but it is not guilty of sin until at some point in its life the infant develops to a state where that inherent tendency expresses itself in willful sin.
Original sin is a tricky one because there is more than one view of original sin.
Some view Paul's comment on OS as simply that ALL are born mortal and sin and as such, all die because they are mortal and sin.
Humankind's tendency to sin is very interesting because, contrary to what you said, observation shows that infants CAN and DO sin on "purpose" and by sin I mean act in a way that is against their best interest, against what is naturally good for them ( case in point a baby lashing out and it's mother for example).
Children have been documented knowingly inflicting pain on each other out of spite or even inflicting pain on animals, knowing full well the impact of what they are doing.
In short humans are born with far more than just a tendency to sin, they are born with a desire to sin, a desire to hurt as an expression of displeasure, and so forth.
Where did this come from?
From man's separation from God.
Man is only truly and fully human when they are in union with God ( as A&E were in the Garden).
Separate man from God and man is in a "fallen" ( less than ideal) state, a state of sin.
