I think we could ask can God be all knowing and not know everything? Jesus who was and is God said He did not know everything. So to your question the answer is also yes.
jesus during the Incarnation limited Himself to operating pretty much as a man at that time, in the kenosis of Christ, he gave up the full function/use of all of his divine attributes, so he was ignorant of his second coming, but since fully reglorified, he again "knows' all things!
And though jesus did not need to know the date, his father still did in heaven, so God still always knew all things!
is the free will of man then limited in that it is ONLY the amount allowed by god, and as such, the creation will ALWAYS be under authority/control of the Creator?
It depends on what it is He wants done. Sometimes man will overrides God's will.
1Th 4:3
For this is the will of God, [even] your sanctification, that ye should abstain from fornication:
1Th 5:18
In every thing give thanks: for this is the will of God in Christ Jesus concerning you.
Not every believer abstains or always gives thanks. God does not always get His will
This is free will.
Matt 23:37
O Jerusalem, Jerusalem, [thou] that killest the prophets, and stonest them which are sent unto thee, how often would I have gathered thy children together, even as a hen gathereth her chickens under [her] wings, and ye would not!
If man had no such thing as free will. Why would God put man through this life we are in? There simply would be no reason for it at all. God is God He can have the results He wants instantly by speaking it into existance. Just seems rather strange to me why such a powerful God would have created all this nonsense. If God doesn't trust man with his own will. Then what possible good would it be to have a man he could not trust? And how can a man trust God, if God doesn't trust him. A relationship is always based on trust.
On the other hand if God wants the genuine article, a man who is willingly submisive to Him, because the man willingly submits to Him. Then He must give man the space to learn from God all of his alternatives and leave it up to the man to either reject or not reject. Other wise God can never know the genuine article of a willfull relationship
No matter whether man has a freewill or not. God is always going to be Sovereigne. Don't let anyone tell you that man's freewill would destroy God's sovereignty because mans freewill has no such effect on God. In fact Nothing can take down God even though He laid down Him Self for our Salvation He also took back His glory. He is still God.
MB