'Furthermore, it only claims the “word of God” is infallible, but no where does it state what is and isn’t the “word of God”.'
Jesus is the Word. It states this at the beginning of the Gospel of John.
Listen, I'm no advocate of Fideism (Roman Catholic here), but isn't the whole point of divine revelation to reveal a God that is, in principle, hidden from the workings of a finite intelligence?