I believe that if we take the Bible as a collection of historical texts written by men with all of their personal and cultural biases that we can get a much clearer picture of the nature of God and of His creation, than if we attempt to understand the Bible as a book authored by God Himself.
Science first defines terms which I find a good rule, one ignored by the theologians down through the ages, tho.
In your OP you postulate that the First Cause was "intelligent, moral, and would necessarily have a vested interest in man and his moral conduct."
Such an Axiom eliminates discussion.
I believe people need realize that this description of a First Cause is foolish.
Intelligence is something man has which he uses to discover what is True and what is not True aout the external world into which he is imprisoned until death catches up with him.
It doesn't follow that the source of the creation in intelligent, de facto that man's intelligence can figure out how the "world" operates.
It does not mean the First Cause even tries to figure out what is true, just because man makes decisions that are a saving grace to him, de facto he behaves in accord with the Truth he perceives.
All we can say is that the creation is orderly enough, and functions in accord to rules, hence men can understand it.
Actually, with that understood, the real god of man is Truth, the light into this weird world we find ourselves from birth on.
That is why John 14:6 says Christ is the Truth.