B. God's Middle Knowledge is dependent on the will of creature. Since creatures could choose differently, God's middle knowledge would be different if they were to do so. Hence, middle knowledge is not essential to God.
C. God's free knowledge includes His foreknowledge of everything that will happen. Since this thrid moment of knowledge is logically posterior to God's creative decree, what God knows wills to happen depends on the world He decrees to create. Hence, had God chosen to create a different world, then His free knowledge would have been different. Therefore, this knowledge is not essential to God either (He could have and still be God).
In order to see that determinism, as that applies to a certain model of free will, has no part in Molinism, I thought I would spell out what it would mean for determinism to combine with Molinism, and then see if middle knowledge even applies to such a model. First off, on determinism, the circumstances God places us in would causally determine our choices and actions. However, on libertarianism and Molinism the circumstances God places us in are non-determined and freedom permitting circumstances; but these circumstances have to be fully specified in order for a determinate truth value to obtain for any counterfactual of creaturely freedom. These circumstances then do not determine our choices and actions, but they have to be fully specified propositionally in order for a truth value to obtain for any counterfactual of creaturely freedom. Do you see? Determinism is a model of free will; whereas counterfactuals of creaturely freedom will not have a determinate truth value if information is not contained in the antecedent. Even though determinate and determinism are spelled similarly they are completely different concepts. One has to do with freedom, and the other has to with propositions have truth values. But worse than that, if you combine determinism with Molinism you can no longer say that God's knowledge of what a creature would do in some set of circumstances is middle knowledge anymore:
"because it will collapse God's middle knowledge either into His natural knowledge (God's knowledge of all necessary truths) or else into His free knowledge (God's knowledge of contingent truths posterior to His creative decree). It will be natural knowledge, if, once all the circumstances and laws of nature are specified, it is logically necessary that one choose a certain way. It will be free knowledge if it is logically contingent how one chooses once all the circumstances and laws of nature are specified. So you can ascribe to God counterfactual knowledge, all right, just as He has counterfactual knowledge of what physical events would happen under various specified circumstances, but this isn't really middle knowledge as such. To count as middle knowledge, the relevant counterfactuals have to be (i) contingently true and (ii) true prior to God's decree."
) Isn't Molinism a kind of indirect determinism? Can't God manipulate the circumstances to get what He wants? The Molinist affirms that we remain non-determined in fully-specified, freedom-permitting circumstances. However, the "counterfactuals of creaturely freedom" have fully specified circumstances in their antecedents. Such counterfactuals have the form "If agent S were in circumstances C, then S would freely do action A." Thus, the counterfactual "If Pilate were in C, he would freely do A" can be true or false only if that statement is determinate in the sense that C is fully specified. But the fully specified circumstances are not causally determining circumstances. On the contrary, they're stipulated to be freedom-permitting circumstances. How an agent would freely choose is not determined by the circumstances he is in. It is simply up to him what he will do. So don't confuse a proposition's being determinate with an action's being determined.
So the Molinist concurs wholeheartedly with you that "if Pilate has libertarian freedom, then regardless of ALL the right biblical conditions, he can still choose one way or the other." Absolutely! He can choose one way or the other; but he will choose one way. If he were in C, he would freely choose A, though he could choose not-A instead. Don't confuse what someone would do with what he could do or think that because he would do A he could not do not-A (Borrowed from WLC).