I think all of these questions point back to God's omniscience. Think about it:
Omniscience means that God knows everything. Not only what is, but what could have been or would have been.
God created the universe as we know it, but He was not constrained to that course of action. Because He is omniscient, NOTHING takes Him by surprise. Also, God's knowledge is logical. I personally believe that there is a possible (counterfactual) scenario in which Christ would not have to have died, but He (being God) chose to come to Earth and die regardless.
What I'm trying to say that prior to God creating the world(s), His knowledge meant that He could have created a different set of worlds, albeit with slight differences from what exists now.
In other words, there is NO possible or logical course of action that God is not aware of.
As the Scripture says, God's ways are past finding out. He knows all the possible choices mankind could make and all the results of them, even if they never come to pass. To use myself as an example, God already knows what I'd be doing if I wasn't typing this right now.
As an aside, this is also why I believe that God's sovereignty does not equal determinism.
$0.02