Serious scientists are giving up on the "big bang" idea and the idea of a supposedly omnipotent and omniscient God suddenly deciding at any given point in time that it would be cool to create a universe (while the idea had never occurred to him in the infinite expanse of time prior to that) is basically nonsensical.
You presume God is trapped by 4 dimensions. Even the Bible alludes to this Psalms 90. In short, God sees time waaaay different than we do.
“the universe at large, like God, is eternal”
This error can be corrected when you learn that God is above all things, including the “universe.”
As for what can be described as “nonsensical,” you must take a careful look at the fact that the last point in your post to me is a declarative statement regarding what you or others imagine God should think, or could think.