Just as omnipotent does not mean God can do illogical things (make a square triangle), omniscient may not mean God can know unknowable things (choice one makes in a universe with free will). This intuition is bolstered by the inherent randomness of quantum phenomena. Not only are we free to choose, it also seems that elementary physical entities are free to "create" an open ended future in a radical way.
Obviously, omniscience does not extend to that which is unknowable. I cannot fathom how anything in God's creation could be logically unknowable to its creator, however. Certainly knowing the future is not normally excluded from claims of God's omniscience. Nor do I think that our own limitations as observers of quantum phenomena necessarily apply to God. WE may be unable to determine a particle's position and velocity at the same time, but there is no logical reason why God could not, for instance.
But predestination does not rely only on logical arguments; if one is a believer in the Bible, then their own holy scriptures offer tremendous evidence that God is in control of everything.
Your eyes saw my unformed substance, and in Your book all the days [of my life] were written before ever they took shape, when as yet there was none of them. --Psalm 139:16
The Lord has made everything [to accommodate itself and contribute] to its own end and His own purpose--even the wicked [are fitted for their role] for the day of calamity and evil. --Proverbs 16:4
A man's mind plans his way, but the Lord directs his steps and makes them sure. --Proverbs 16:9
The lot is cast into the lap, but the decision is wholly of the Lord [even the events that seem accidental are really ordered by Him]. --Proverbs 16:33
Many plans are in a man's mind, but it is the Lord's purpose for him that will stand. --Proverbs 19:21
Man's steps are ordered by the Lord. How then can a man understand his way? --Proverbs 20:24
O Lord [pleads Jeremiah in the name of the people], I know that [the determination of] the way of a man is not in himself; it is not in man [even in a strong man or in a man at his best] to direct his [own] steps. --Jeremiah 10:23
And when the Gentiles heard this, they rejoiced and glorified (praised and gave thanks for) the Word of God; and as many as were destined (appointed and ordained) to eternal life believed (adhered to, trusted in, and relied on Jesus as the Christ and their Savior). --Acts 13:48
We are assured and know that [God being a partner in their labor] all things work together and are [fitting into a plan] for good to and for those who love God and are called according to [His] design and purpose. For those whom He foreknew [of whom He was aware and loved beforehand], He also destined from the beginning [foreordaining them] to be molded into the image of His Son [and share inwardly His likeness], that He might become the firstborn among many brethren. And those whom He thus foreordained, He also called; and those whom He called, He also justified (acquitted, made righteous, putting them into right standing with Himself). And those whom He justified, He also glorified [raising them to a heavenly dignity and condition or state of being]. --Romans 8:28-30
And not only that, but this too: Rebecca conceived [two sons under exactly the same circumstances] by our forefather Isaac, and the children were yet unborn and had so far done nothing either good or evil. Even so, in order further to carry out God's purpose of selection (election, choice), which depends not on works or what men can do, but on Him Who calls [them], it was said to her that the elder [son] should serve the younger [son]. As it is written, Jacob have I loved, but Esau have I hated (held in relative disregard in comparison with My feeling for Jacob). What shall we conclude then? Is there injustice upon God's part? Certainly not! For He says to Moses, I will have mercy on whom I will have mercy and I will have compassion (pity) on whom I will have compassion. So then [God's gift] is not a question of human will and human effort, but of God's mercy. [It depends not on one's own willingness nor on his strenuous exertion as in running a race, but on God's having mercy on him.] For the Scripture says to Pharaoh, I have raised you up for this very purpose of displaying My power in [dealing with] you, so that My name may be proclaimed the whole world over. So then He has mercy on whomever He wills (chooses) and He hardens (makes stubborn and unyielding the heart of) whomever He wills. You will say to me, Why then does He still find fault and blame us [for sinning]? For who can resist and withstand His will? But who are you, a mere man, to criticize and contradict and answer back to God? Will what is formed say to him that formed it, Why have you made me thus? Has the potter no right over the clay, to make out of the same mass (lump) one vessel for beauty and distinction and honorable use, and another for menial or ignoble and dishonorable use? --Romans 9:10-21
Even as [in His love] He chose us [actually picked us out for Himself as His own] in Christ before the foundation of the world, that we should be holy (consecrated and set apart for Him) and blameless in His sight, even above reproach, before Him in love. For He foreordained us (destined us, planned in love for us) to be adopted (revealed) as His own children through Jesus Christ, in accordance with the purpose of His will [because it pleased Him and was His kind intent] --Ephesians 1:4-5
[He planned] for the maturity of the times and the climax of the ages to unify all things and head them up and consummate them in Christ, [both] things in heaven and things on the earth. In Him we also were made [God's] heritage (portion) and we obtained an inheritance; for we had been foreordained (chosen and appointed beforehand) in accordance with His purpose, Who works out everything in agreement with the counsel and design of His [own] will, --Ephesians 1:10-11
For we are God's [own] handiwork (His workmanship), recreated in Christ Jesus, [born anew] that we may do those good works which God predestined (planned beforehand) for us [taking paths which He prepared ahead of time], that we should walk in them [living the good life which He prearranged and made ready for us to live]. --Ephesians 2:10
There are others; if you need more, let me know.
An omnipotent God can surely make your described best possible world come true without causing an iota of suffering to anyone else. It's very hard to hit the contra-logical constraint with omnipotence.
You say an omnipotent God can "surely" do this, but it is not "sure" or self-apparent that this is true. We do not know, and we CANNOT know, without the benefit of omniscience ourselves, that ANYTHING in this universe could be different without negatively affecting it.
What we DO know, logically, is that an omnibenevolent God would want to create the best of all possible universes, that an omniscient God would know how to create the best of all possible universes, and that an omnipotent God would have the power to create the best of all possible universes. Therefore, we ARE logically constrained to accept that IF an omnibenevolent, omniscient, omnipotent God exists, then we live in the best of all possible universes, and any "evil" we see in it is only that amount of evil that is logically necessary to the best of all possible universes.
There is no need for creatures without free will to know the difference between pleasure and pain or good and evil. A pleasurable experience does not logically require a painful experience to be enjoyed. Otherwise one needs to be old first to enjoy youth, blind first to enjoy sight and die first to enjoy being alive. And what use is knowing good and evil without free choice to act on that knowledge?
You say you see no need for creatures without free will to know the difference between good and evil, but I can see the value in that. If I was God, and I wanted my creations to understand and appreciate My goodness and the goodness in My creation, then I would have to give them a mechanism by which they could come to that understanding--and the only way that is possible is by contrasting goodness with evil. Then they will be able to appreciate heaven when they get there, because the evil and pain and suffering will all be conspicuously absent.
And yes, pleasurable experiences DO require the concept of painful experiences (or at least experiences that are "not-pleasure") in order to be enjoyed. If you went about your entire life, from birth to death, in a state of orgasmic bliss--you would never know it because you'd have nothing to compare it to. It would just be "normal." There would be no word for pleasure, because it would have no meaning--nothing is "not-pleasure." And the same goes for your other sets of opposites--you may not need to experience blindness yourself to understand what sight is, but you wouldn't understand either concept if eyes were universal, they could never be damaged or removed, and they always worked perfectly. Sight would just be a given. People would think you were an idiot to suggest that such a thing as "not-seeing" even existed. It is only in recognition of our own mortality that we DO appreciate life, even if we don't have to actually die before we can appreciate life. And people often DO say that youth is wasted on the young, because they don't fully appreciate it until they are older. In any case, if there was never any aging, and everyone was born physically equivalent to a healthy 18 year old and everyone died physically equivalent to a healthy 18 year old, then "enjoying one's youth" would not logically be possible, because there would be nothing that is "not-youth."
Not possible IF there is no free will AND we do have an Omnibenevolent Creator God. Your own example shows what an evil superbeing would do in a universe without freedom of will. Hence, it logically follows that a good superbeing would do the exact opposite if He created a universe without free will. He would make a universe where its non-renewable willed inhabitants will continuously experience maximally blissful experience and maximally meaningful existence.
I'm beginning to wonder if maybe we should define what "possible" is. You seem to be excluding things as being impossible when you don't understand them or don't think they're likely, but neither of those conditions rules out possibility. Just because you think you know what God "would" do, doesn't mean that it's impossible for Him to do anything other than that. When I say that an omnibenevolent God would want to make the best of all possible universes, that's implied in the definition of "omnibenevolence." An omnibenevolent God is logically constrained to create the best of all possible universes. But it's NOT implied that every creature in creation will continuously experience maximum bliss--so you can't logically conclude that God is constrained to that action--there are other possibilities.