However, I can’t make the leap of faith (and it is faith — faith in an idea) that assumes that Hs’s capacity for creative imagination is the product of a biological process.
No, what takes faith is the idea that man's creative output is somehow so fundamentally different than the material world that a natural process can't be the explanation.
It's your position which is faith-based, not ours. Furthermore you betray an ignorance of the creative process.
Hs is a creator, meaning that he makes things out of nothing.
Nobody makes things out of nothing. Shakespeare wrote his sonnets, drawing on a hundred years of Italian sonnet poetry. He wrote his plays drawing on centuries of pre-existing drama. In some cases he outright plagarized popular comedies and gave them his own slight twist.
Like evolution, the human creative process is not one of creation ex nihilo, but of slight, successive modifications of what came before.
Natural selection doesn’t make arbitrary choices.
I don't see what that has to do with anything. Why do all products of natural selection and random mutation have to share every character of those two processes? Are you suggesting that your choices and ideas must have an origin seperate from your brain? That they come from outside you, somewhere?
Why can't natural selection give rise to characters different from natural selection? You're going to have to defend that point before we're prepared to accept the rest of your argument.
And are the sciences the only place to be looking for an explanation?
Aside from rational empiricism, by what other means would we arrive at reliable information about the universe? Nothing else has the power to distinguish fact from make-believe.