An interesting post, Omnivinco. The problem with it, as I see it, is that the argument is based on beliefs that some Christians hold but are not essential to the faith. Questions of the sovereignty and meaning of omniscience and other attributes have been going on for, well, as long as humans have contemplated higher powers. As an example, you may be interested to learn a bit about open theism, which it seems more or less directly addresses your question: https://iep.utm.edu/o-theism/

As for the 70% of humanity doomed, no doubt there are Christians who believe and teach that, I'm not one of them. There are other Christians such as Origen, George McDonald and Teresa of Avila who disagree. Teresa, as I heard Richard Rohr explain, believed that there was a hell but no one was in it. Personally, I believe CS Lewis' marvelous little book The Great Divorce deals with this issue in a storytelling way that only he could do.

Critics of Christianity like to select specific beliefs of specific groups of believers to undermine. Fair enough, I suppose. But arguments against the foundations are more difficult to respond to. As to my ideas of the foundations, you may want to read: https://gerald-baron.medium.com/exploring-christian-belief-today-47ca0b27751c

Best to you,

Gerald