1 - Does omniscience necessarily mean God knows the future?

yes, but carnal minds dont grasp it

>2 - If God knows the future, can we possibly have free will?
>If He knows what will happen, aren't our choices already
>set?

first lets discuss will, yes we are free to live at our own will but know what happens when you choose to. Our Creator prefers we do the will of Him and not our own, how can a man understand his own ways? he cant! the heart is tricky, tricky, tricky. that is why the Most High said lean not toward your own understanding but mine.

3 - If we have free will and God doesn't know our choices
>(and therefore the future), can he be considered omniscient?

not applicable

>What do you think? Personally I believe in free will
>(although I do think there is evidence of divine
>intervention on earth) but I wonder if/how God can be
>all-knowing and all-powerful when we have free will? Somehow
>I want it both ways...

we have free will but that doesnt mean do whatever "you" think is right in your own eyes because it will only get you but so far. God desire is that we do His will if not we can only blame ourselves. we need to recongize who we are dealing with, once that is done your will doesnt matter, but doing His will. You realize that free will means nuthing. and God "grants" it because he is also merciful