The 'created light of glory' Aquinas refers to there is the lumen gloriae
. It does not inhere in God, but in the mind of man. Or at least, in God's action in the mind of man rather than in God simply. Thomas:
Nothing can receive a higher form unless it be disposed thereto by raising and enlarging its capacity, because every act is limited to its proper power. Now the divine essence is a higher form than any created intellect. Therefore, in order that the divine essence become the intelligible species for a created intellect, which is required in order that the divine substance be seen, the created intellect must be raised and enlatged for that purpose by some supernatural disposition. (16)
When any created intellect sees the essence of God, the essence of God itself becomes the intelligible form of the intellect. Hence it is necessary ... that the power of understanding should be aided by divine grace. Now this increase of the intellectual powers is called the illumination of the intellect
On the issue of the Papal Infallibility, it is not held by the Catholic Church to be theoria
which you are free to agree or not agree to. The First Council of the Vatican, in explicit language, places anathema on anyone who fails to assent to it.
Either way, his personal views on it aren't the views of the Catholic Church.
I'm sorry, but his personal views are exactly the views of the Catholic church if he chooses to make them so. I'm familiar with some of the nuances of the doctrine of infallibility, and any time the pope chooses to speak "from the magisterium," he is to be regarded as speaking "infallibly." That's the deal, like it or not.
We Orthodox don't like it, needless to say.
That statement wasn't made with reassuring any Orthodox in mind, it was a statement made by a Catholic about the Pope, made to another Catholic, self-identified. Anyways, no, the Pope can only define what has been taught by the magisterium. He has no authority to codify anything that doesn't fall under the teachings of the magisterium.