I'll have one main comment on all of Question 2, but I may interject a couple remarks on each of Articles 1-3.
It would actually be very difficult to overstate the contemporary importance of Thomas's having taken ten articles to arrive at the question of God's existence, and then taking two steps
before broaching directly that question itself. One of the luminaries in the
Communio circle, albeit not wholly uncontroversial, has actually published (and, after criticism, republished in a revised second edition) a
book which I found terribly helpful in the middle of my crisis of faith and literary theory:
Dieu sans l'etre: hors-texte (
God Without Being by Jean-Luc Marion).
Now, I'm not even 100% sure I still track with some of the philosophical premises that I seemed to share with Marion's approach when I read him back in 2008, but I keep meaning to re-read him to find out. What I am sure of is that since Modernism has identified "realist" knowledge with a totalitarian vision of reality comprehended and controlled by technical means in service of an unknowable unity between the most extremely individual, inarticulate "gooey center" of each person and the most unknowably sublime "outer limits" of collective aspiration, it has become increasingly difficult to articulate what a thinker like Aquinas means by seeing revelation as God's having given us in part what He has in whole: an identity (not a mere resemblance) between truth and reality.