most theologians do exactly this
I would disagree. I don’t think “most” theologians do this. If you want to make a general claim that most theologians do this, then you’d have to prove that, which I again, I would say you are wrong about that.
define omnipotence and omniscience such that free will is possible
Omnipotence: Having unlimited power.
Omniscience: knowing all things.
Now these don’t deny free will in anyway. Aquinas answers this perfectly in how he sees contingent things in relation to God’s omniscience, seeing this is where you are having an issue.
Aquinas says: "
It is written ([Psalm 32:15]), “He Who hath made the hearts of every one of them; Who understandeth all their works,” i.e. of [men]. Now the works of [men] are [contingent], being subject to [free will]. Therefore [God] [knows] future contingent things."
So, first, we can say, even if you limit God’s omniscience, which by the way means God is not omniscience, because limited knowledge isn’t all knowledge, and limiting God’s knowledge also leads to saying that God can learn things He did not know, which then leads to saying that God is not fully perfect in everything, including His knowledge, so limiting God’s knowledge degrades the rest of God. But if you limit God’s knowledge, you still would admit that God knows all actual things. For if God knows all things past and present, as you seem to say He can only know, to try and save libertarian free will, then He has all knowledge of actualities, since all things in time that have actually happened so far have actualized. But then the question comes of whether or not God can know potential things? I would assume you would agree with that since the issue you have is God knowing contingent future things, not future potential things. So if we agree, God then knows things that are not, since potential things are not actual, and God knows all things that are actual, at least in the present and past if you will hold that there are not actualities in future until the future becomes present and past.
Now, where does that leave contingent things? Since God knows all things actual, he also knows all things possible to Himself and His creatures, and since some of these are future contingent to us, it follows that God knows all future contingent things.
Now God must know all future contingent things in their causes as well, for contingent things become actual successively, but God’s knowledge is not in time, therefore His knowledge doesn’t view things successively but as a whole, simultaneously because of His eternity. Hence, all things in time are present to God from eternity because His glance is carried over things in eternity as they are in their present. Therefore, it must be said that future contingent things must be known by God infallibly inasmuch as they are subject to the divine sight in their presentiality, and yet they are contingent things in relation to their own causes.
CONT