If he is unbound by time, and was there when it happened (so he knows), it's not because he pre-established the outcome, but because it already happened.

There is no pre-determined path to those events. He only knows because he was there when it happened, before it happened (like the definition of foreknowledge you provided also states).

Not a very solid foundation you're on. You're basically saying since he has one option to view decisions in a non-temporal manner, that negates his ability to view them in one. An omniscient being would view them in every manner; as such, the temporal view is certainly subject to the same logical statements I've presented.

Simple example:

Milk or OJ <-- your illusion of choice, the ominscient being already knows you've chosen one of them. You cannot choose a different one than is already known. 

He knows, only because you made the choice already. But he knows before you made the choice. He only knows based on the foundation that the choice was already made. That's foreknowledge.

How can their will be free if every single action that they are going to make is set in stone? That is the opposite of free will. And going back to your OP, how does he not know why you have made/will make each decision in your life despite being able to analyze every single atom in your body (well, brain mainly) and your entire soul? How does he not know when he supposedly is all-knowing?

The underlying issue is that God cannot create a universe in which the future cannot be predicted by him, despite being almighty. Just like he cannot create a god that is more powerful than him, despite being almighty. God is a paradox.

Many neuroscientists will disagree on this.

Or they would at least point out that there is not one single notion of "free will". Just like "god", the concept of "free will" is much more vague than most people realize.

I'm afraid it sounds like you've simply created a paradox.

How can an almighty god make itself not almighty.  If the god is almighty it must be omniscient. If the god is not omniscient then it cannot be almighty.

This is also known as the omnipotence paradox, an example being:

Can god create a stone so heavy that he cannot lift it?

You are misunderstanding what foreknowledge is. Foreknowledge isn't going to time t to witness a particular decision then moving back to a time prior to t to wait for it. It's knowing before witnessing the decision.

You have not made any decisions at time 0, but an omniscient being already knows every outcome. <- this is foreknowledge.

One fatal flaw though.
People make decisions based on coin flips at times.

If god knows then your choices are predetermined. We just choose to believe we make our own path in that instance.

I believe we're both correct, my mistake. Foreknowledge is a word that simply means to known in advance. Whether the actions can be predetermined (your scenario) or not (the one I presented), in both cases the being has foreknowledge.

The question remains, how is it possible for something that can't be predetermined be foreknown? Simply by virtue of being unbound by time. If I know something before it happened, because I was also there when it happened, then I have foreknowledge.

@prof. Not really. Think about it.