Earth, you have an OP that's about a foot and a half of text.
You end it with this statement:
For debate: Any arguments theists could give to justify the acceptance of unfalsifiable religious claims about divine creation in the absence of a solution to the universal problems of confirmation bias, induction, and underdetermination.
Do you mind repeating that in words that are easy to understand?
The specific request in the post above was reasonable and relevant, so, I will at least make a good-faith effort to address it:
Consider, for example, the theistic claim that a god answers prayer. When you ask most theists if an unanswered prayer would function to falsify the claim, they almost always and consistently argue that such an outcome would not disprove their claim. So, what reasonably obtainable evidence would those theists expect to find if their claim about a god answering prayer is false? There is not an answer to the question because the claim is unfalsifiable.
Well, if the theist has no way to ever discover if their claim about a god answering prayer is false, what is the justification for believing it is true?
To understand why these unfalsifiable claims are problematic, let's return to the "all swans are white" claim to simplify the explanation. Prior to the discovery of a black swan, European naturalists had only ever observed the existence of white swans. So, the evidence for the "all swans are white claim" was their prior observations of wild swans in Europe that were always white in color. Therefore, all the available evidence seemed to confirm the "all swans are white" claim. Of course, given the benefit of our hindsight, it is relatively easy for us to understand where the
universal problem of confirmation bias existed in their argument for the "all swans are white" claim. However, from the limited perspective of the European naturalists who weren't aware of a black swan existing in Australia at the time, they thought it was perfectly reasonable for them to believe that all swans were white given the supporting evidence.
Furthermore, the European naturalists felt it was reasonable for them to inductively infer from all of their previous observations of white swans that the next swan someone observed in the wild would also necessarily be white. Again, given the benefit of our hindsight, it is easy for us to understand where the logical fallacy exists in their inductive inference at the time. Obviously, if the next observation of a swan happened to occur in Australia, it would not have been white but black in color. That outcome demonstrates the
universal problem of induction.
Last but not least, the universal problems of confirmation bias and induction demonstrate how evidence for a claim will always
underdetermine what should be believed about it. Despite all the available evidence seeming to confirm the "all swans are white" claim and the expectation that the next swan observed in the wild would be white as well, the idea was false nonetheless. So, the supporting evidence on its own was never sufficient to justify the belief in the corresponding claim. What eventually resolved these problems for the European naturalists was the fact that the claim turned-out to be falsifiable by the observation of a black swan in Australia. Had it not been falsifiable, what logical justication could the European naturalists have provided for accepting the "all swans are white" claim if they could never observe every swan in existence on the planet at the time?
Arguments for unfalsifiable theistic claims are fallacious for the same reasons unless you or any other theist can provide a logical justification for accepting them in the absence of a solution to the universal problems of confirmation bias, induction, and underdetermination. I hope this explanation was sufficiently simplistic to provide some clarity.