Isaias 1:19 If you be willing, and will hearken to me, you shall eat the good things of the land. 20 But if you will not, and will provoke me to wrath: the sword shall devour you because the mouth of the Lord hath spoken it.
*There are other OT verses of course. Y'all couldn't throw everything out of the Bible :)
Eze 36:26 "Moreover, I will give you a new heart and put a new spirit within you; and I will remove the heart of stone from your flesh and give you a heart of flesh. (God's sovereignty)
To complete Augustine's logic you have to conclude that when God states that He will give us a new heart and spirit and cause us to walk in His statues, He means just that. Since God is perfect, His "new heart and new spirit" gift to us will also be perfect.
You can post all sorts of "free will" verses just as I can post all sorts of "God's sovereignty" verses. However, you will never get past the Augustinian logic above. You will never be able to satisfactorily explain Ezekiel 36. All I'll ever here is "yeah but this verse over here says...".
OTOH, for Ezekiel 18 I would simply answer as Augustine would answer, that God commands what He wills and gives what He commands. He gives us a new heart and spirit as He states in Ezekiel 36 and then He commands us to use it as in Ezekiel 18. God promises that this new heart and spirit will allow us to walk in His statues man. It's all because of God's working. If God so empowers us, it will happen.
This is exactly the way He works with all your verses.