I went on a similar journey a while ago and came to strikingly similar conclusions. In fact, I grew up contending with colloquial arguments for theism--especially from stereotypical Protestantism--as I found none of them convincing; I then explored some of the more prominent figures in the mainstream debates in theology (such as the new atheists, william lane craig, etc.) and found them likewise unconvincing; and then, eventually, I came across Ed Feser's "Aristotelian Proof" and it was bizarrely different than any other argument I had heard. I didn't find it convincing, but I started reading on Acquinas, Aristotle, Augustine, Plato, and the like on classical theism and found the argumentation for and metaphysics of God vastly different than mainstream theology. In short, I ended up convincing myself, somewhere along that journey, of the classic theism tradition.
Where I think this becomes particularly interesting is that questions like the problem of evil take on a different character. If God is not a being among beings but Being itself, then the moral structure of reality flows from the nature of God, who is goodness itself, rather than from some being telling us how we should live. What does this mean for the problem of suffering?
Yes, indeed it does: it becomes interesting (I would say) for all topics in theology. God is the
ipsem ens subsistens, the
actus purus, divinely simple, an intelligence, a will, the ultimate cause of everything's active existence, etc.; and it follows that:
1. God's willing a thing as real is identical to Him thinking of it as real.
2. God
qua intelligence and
qua pure actuality cannot think of a thing as real other than relative to its perfect form.
3. God, then, cannot will a thing into existence in a manner where it is not in correspondence with its good.
4. So God must be all good willed.
So why is there badness in the world then?
Because:
1. Creation always entails a hierarchy of value of goods.
2. When that creation is willed in a perfect manner (viz., the good of each thing is willed in accordance with its perfect form respectively) and given #1, this allows for the possibility of privations.
3. Those privations are not willed by God: they are the absence of good.
This is also why Acquinas rightly points out that the euthyphro dilemma is a false dilemma: God is perfectly good, He then must be perfect at what He is, and He then must be perfect at being an intelligence, and so He wills what is good exactly because He is perfectly good. His goodness is out of necessity---not by choice.