To my understanding, these questions about wholesome/unwholesome and rebirth/kamma are considered much less “ultimate nature of reality” than such things like “viññāṇa anidassana” or “Nibbāna”.
I am not sure about you but for me, I consider those Scenario 1,2,3,4 that we have gone through are models to help understanding our ideas. However, ideas are plenty and only the most useful ideas can stay. Therefore, I consider those questions as a test to see how well these ideas can be useful to us and to abandon unuseful ones.
So, in that perspective, those questions are really essential and can not be ignored. If they are ignored, that means there is a serious drawback/hole in the idea. If that drawback/hole can not be fixed/patched then that idea should be replaced by a better idea which at least passes the test.
I hope that I have conveyed to you and you also confirmed that I have fairly understood what you meant by “viññāṇa anidassana”/“undefiled mind” or “Nibbāna” through the analogy of Scenario 4. However, as explained above, due to the above limitation of ignoring essential questions about wholesome/unwholesome and rebirth/kamma, I can not accept these ideas.
Instead, as I said from beginning, I propose Scenario 2 as a better candidate. You are welcome to do similar tests toward Scenario 2 by asking essential questions and I will try to answer you. Of course, even if I manage to answer all of your essential questions, in the end, you will still be the one to decide which Scenario to rely on for your own spiritual journey.
Another possibility is: You can just conclude this discussion here and simply know for yourself that there are limitations of your ideas and there are other ideas (which can be better and be supported by suttas) that you today simply chose not to explore further.