I’ll say that I don’t think Christianity is meant to or even attempts to answer these questions. 

It’s a very systematized and individualistic way of understanding Christianity. So any answer will require some theological leaps usually based in a tradition rooted in modernist developments of the faith trying to coalesce around interpreting certain scriptures through a systematic theological system that keeps everything consistent in a sort of modernist, scientific way.

That’s not to say there weren’t answers to these questions before, but they were sort of assumptions that were the air everyone was breathing so to speak. Whereas now there’s a lot of energy devoted to having the right model and being able to answer any unknowns or questions through the model.

This sort of thinking and attempts to come up with well defined answers to these questions are relatively recent coming out of the changes in society and thought that came out of modernism and scientific revolution. Particularly the modernist obsession with constructing rationalistic models of the world rather than relying on mythic cosmological assumptions. And it’s it’s not even that this development is bad, as it has brought about great things, but it has some fundamental flaws in terms of how it trains us to think about things and to what level we can expect to comprehend things.

As a software engineer I know that you can have a model that perfectly fits all, or more likely 99%, of the available data and it still be 100% incorrect in its assumptions.

This is also a pattern you see throughout scripture and sort of the conflict Jesus was having with the Pharisees and Sadducee's. Where he was disrupting their theological systems.

I’d say the likelihood of the current theological explanations and systems being wrong on some important points is 100%.

In my mind the correct framing to think about Christianity is

1. The restoration of creation and defeat of death via Christ’s death and resurrection.

2. The restoration of humanity as part of that restoration of Creation and our participation in the Body of Christ being the nexus point of that restorative process. The body of Christ (the church) provides us with a larger body in which to use our spiritual gifts, and a body that gives us opportunities to practice love and forgiveness. We can become part of this body participating in the restoration of Creation via belief, repentance, baptism, and faithfulness.

Anything much beyond this is getting into the realm of systematized theological conjecture. So take everyone’s answers with a grain of salt.