Good evening! Please forgive this rather short and haphazard response as I’m attempting to offer some measure of response via the mobile.

To start with the fall, it wasn’t just knowledge, but the fruit of the tree of the knowledge of good and evil. We don’t know why it was there, but they were told not to partake of it, or their transgression would result in the fall and blighting of creation, along with their (and their descendents) subsequent death. They were made in the image of God and, as such a (somewhat pale) reflection were made the pinnacle of what they could be and, especially, to be able to exercise their minds and free will. So if Adam did walk and talk with God, his Creator, in the garden, then he would have known exactly who God was and the implications of it – in both God’s sovereignty and His will to sustain and care for His creation.
The crux of the fall came not that they wanted knowledge, but that they were influenced to doubt the very words and experiences that they had personally had with God – but more so that they gave in and acted on that externally negative influence. They were not made corrupt, but they enabled their corruption.
So why would God then continue to punish them even though they fell because of an external influence? Firstly, because they are responsible for their part and acting on it and, secondly, because God is Holy and Sovereign – if God has said that something must be so, then it must be/become so – He cannot go back on His Word because He is the absolute and self-sufficient one, against which all of His own creation is held. He must do what He said because He is not a corrupted man who created corrupted man, but the Supreme and perfect God. He is known as the judge because He has kept to His word and is the only one truly righteous to be able to hold any to account by His Law. If the first transgression is anything to go by, then breaking God’s Law comes at a cost – as it is said, ‘the wages of sin is death’. So, to honour God you give to Him the best that you have of the first of what you make (E. G. Abel), but also, the cost of something must be met, with a transgression valued at the cost of life needing to be met. Thus the later sacrificial system was established. Notice that even before they were cast out of the garden, God had set in motion events leading to the reconciliation of all creation (including humanity) to Him, and even more so, provides the man and woman with clothing, making the first partly atoning propritiatory sacrifice Himself.
With the wages of each instance of sin being death of the transgressor, then how could the OT sacrificial system, offering a substitute for the law-breaker actually make a man right with God, if, by His corrupted nature, he will naturally reject and despise the God who despite this continues to sustain him? Shortly, it can’t.
Facetious, only part of the interest is being paid off a mounting debt.
Multiply that up for every person to have lived or will live and all the transgressions they will commit, and be His (more on this in a moment), and all of creation, then you are left with an almost infinite debt.
Jesus took on that debt by, not only living and being without sin (to again refer to sin as transgression against God) and living by faith in perfect obedience to the Will of God, but being able to overcome the cost by being the Son of God and God the Son, not a created (though having become incarnate and taking on flesh), but infinite (if willingly limited during the incarnation) being of infinite worth. It was a debt that only God could pay because, beyond realising their inadequacy and dependency on God and pursuing God in that manner, there is nothing that an autonomous created being could ever offer their Creator that could ever influence Him to think or look favourably on them. These offerings are all the more grotesque if offered in a sinfully self-possessed way (like the idea that someone will get into God’s good books if they live a good life).
Thus the issue of the BC believers comes down to who trusted in God and, furthermore, trusted in His promises, especially of deliverance, however long it took them to do so. These were all, including prophets, patriarchs, high and low, very human and prone to failure but, ultimately, they placed all their trust in God and not in their own abilities. And if trusting in God and as a result/stemming/subsequent attempt at living a life for and with God provides the best life that can be had, then the cycle returns to Eden and the doubt instilled therein. The choice returns to trusting and seeking God.

God continually provided and provides a way to be reconciled to Him. God continually sustained and sustained (re: common Grace), but if God went to the effort to create and then instill His creations with the ability to choose to follow or reject Him, why should He override that ability and make them mindless automatons? Why should God dish out blanket reconciliation to those who would continue rejecting Him regardless? The wages of sin is death and it is a price that must be paid – by you or by Christ. But only one will bring reconciliation to God and only one can meet the debt of a life of absolute rebellion against Him.

Regarding Hell – depends on which translation of two different places and states, unfortunately translated to the same English word – oft in the OT, there is reference to sleeping in the Bosom of Abraham, or also considered to be the rest in the state and place of the dead, while there is much reference in the NT, more often by Jesus, the place of destruction (Gehenna – symbolised by a fiery place outside Jerusalem where refuse and whatnot was burnt and destroyed). Incidentally,most of what is known about this place of destruction has been supplied by Christ.

Nothing changes or has changed about the ultimate end of one who rejects God. For if God is so completely different and perfect, the standard against everyone is held, then God is completely right and justified to pronounce sentence and mete justice against anything and anyone that falls short of His Glory.
God doesn’t and didn’t want anyone to perish, but He must hold to His own Law, which the person, life and propritiatory sacrifice His Son and incarnation is the culmination, completion, fulfilment and fruition thereof.
And it is faith in Him and His work which reconciles, regenerates and begins the sanctification of the believer.
Everyone is given a chance (sorry, won’t go into discussion of the doctrine of the anonymous believer atm), and often many.

Judas Iscariot did not have to betray Jesus. He knew all there was available to know, had seen all the miracles and transformations that Jesus had wrought, had lived and worked with Him for years, yet he still betrayed Him. Maybe for some it is more pity for Judas, because they can see the same pull toward such transgression in themselves – can see how easy it would be and really don’t like it?

Anyway, please excuse and pardon me – must be off. Hope this offers some semblance of honest and helpful response (despite formatting) – I don’t know very much and understand less, but the little that I do comes from the work and incredible mercies and blessings of God in my life. I very much hope this helps. R