Our finite minds cannot comprehend the Infinite without the Holy Spirit. A simple question that cannot be answered scientifically is infinity into the past. It doesn't make sense, and it defies logic and rational thought. Let's say the Big Bang was the beginning of the universe and evolution in general. Well, what caused that? And, whatever caused the Big Bang, what caused that, and on and on it goes into infinity past. God is eternal--that's the simple yet profound answer the Bible provides.
You are correct, I believe. Any explanation for the state of things before the beginning of the present creation is theoretical and will have flaws when viewed from a position after the beginning. We should avoid dogmatism on theoreticals and honestly represent andbe willing to acknowledge the problems with our particular theories IF SO-AND-SO's PRESUPPOSITIONS WERE CORRECT. But we do not have to agree with any particular philosopher's or theologian's presuppositions.