The fact that God is good in no way seems to restrict the actions of God. There is nothing conceivably that God can do that is evil (according to you).
I think what he means to say is that God, being the measure of all things, is good in concept and being. That is to say, whatever is considered "good" is only because God has decreed it. Since he is the measure of all things, goodness and God are therefore synonymouy. Conversely, anything contrary to God is considered evil, so that the anithesis of what is good is evil.
However the actions of God are limited by what is illogical according to you. We can conceive of things that God cannot do because they defy logic (e.g. create the uncreated).
Thus logic defines what God can and cannot do rather than the other way round. Logic is not defined by God. In fact logic appears to bind and restrict the possible actions of God.
I would agree with that theologically. Anything that man considers "illogical" or impossible actions that defy the laws of nature (Jesus walking on water) are not logical to humans. In fact, it is illogical. Thus I would have to concur with your statement to a degree, but I also understand what he is trying to convey. He is trying to convey that God is the template.
Can you think of something God cannot do because it is illogical?
Because it is illogical? No. I don't think it applies. Logic applies to man who is bound by laws of non-contradiction and physical laws which would prevent him of doing something. God is presumably under no such restriction for a number of theological and philosophical reasons.
Can you think of something that God cannot do because it is evil?
Yes... God cannot sin, theoretically, because God is goodness. God can only do things according to what he is.
God cannot break a commandment because he doesn't fall under the juristiction of his commandments.
In a sense, but it may make more sense to say that God wouldn't break what he supports.
“Tu ne cede malis sed contra audentior ito"
™ Version 4.2