I just realized, stemming from the "God is omniscient so we don't have free will" argument:
Since God knows all, past present future, God must know his own future, past, and completely know his own self. Therefore, he knows exactly what his will is AS WELL AS precisely what actually will happen. Therefore, God does not have free will because, being outside time, he does not have the ability to make a decision that he has not already predicted infinitely accurately, so God does not have free will and is thus not all-powerful.
Even if there were a loophole in this argument stemming from whether free will is required to be all powerful, it still doesn't work. God becomes nothing more than a robot of infinite power unable to do anything but follow his programming. But then it leaves to wonder-if God already knows everything, where did the knowledge of the future come from? Creation cannot previously exist, and since God is not defined to be knowledge, God must have somehow created the knowledge of the future and of time, and therefore must have been at one point not omniscient. But if the knowledge was already there at all times and God already knew it and just follows it, then God becomes nothing more than a superpowerful robot performing exactly according to programming.
Therefore, logically, God (nor anything else) cannot be omniscient without becoming a slave to knowledge, and cannot be omnipotent without sacrificing knowledge of the future.