"An omnipotent, omniscient god could very well create free will - although that would require that he limit himself, which would then make him a limited god."
I beg to differ. Limiting oneself, by choice, does not contradict omnipotence. On a merely human level, the fact that I have the ability to do something does not change simply because I choose not to do it.
If a god remains both omnipotent and omniscient (and also actively engaged) then free will is an illusion. In the absence of free will, god is irrelevant to us from a practical standpoint because there is nothing for us to decide. Nothing happens that is not precisely what the god wants to have happen.
If anything happens that is not precisely what the god wants to have happen, then he is a limited god - even if self-limited. Events are taking place that are contrary to his will. And again, creating the option to engage in evil is creating evil.
Free will is not infinite. I do not have the free will to flap my arms and fly away to the moon of my own volition. Teleportation, telepathy, invisibility, immortality, perpetual youth - I can freely will none of those, nor a myriad of more mundane actions.
Once the will is finite, then it has parameters. If a god created free will, god defined the parameters. If he defined the parameters to include the enactment of anything he deems evil, then he is either an evil god or a dualist god. An evil god, to whatever degree, is rationally irrelevant, because he lies.
He could also be an irrational or a capricious god - but those are practically irrelevant as well.