Um yes. Catholicism is faith based. When you state " Whatever answer works for the Trinity works just as well for the universe." I take that at it's face value. The answer that works for the Trinity is faith. Feel free to edit your statement.
As for fairy tales, I have no opinion or interest in what you do or do not consider to be fairy tales.
Uh, yeah, and as you yourself pointed out when you incorrectly thought that would be my answer, that answer works equally well for the universe.
Either God created the universe or the universe created itself. Which is more fantastic?
As I pointed out, whatever answer works for God works for the universe. So, it is no less "fantastic" to think that the universe created itself, or that the universe is eternal and uncreated, than it is to think that God created itself, or that God is eternal and uncreated.
Whatever the answer it doesn't matter. It will work equally well for the one as for the other, in terms of rational credulity.
Well, except for the fact that the universe demonstrably exists.