An assistant professor of religion at Augustana College, Dr. John Anderson deals with a spate of new books that have recently been published that asks this question. The comments are pretty good, also. I strongly urge you to read his post Is God Moral or Immoral.
As you read his post and the comments, keep in mind that distinction between what is moral and what is ethical. We often conflate the two. Here’s the bottom line:
Suppose God establishes truth as a moral value. An immoral person is one who rejects truth as a moral value. Now, suppose Jim believes in, and values, truth. If Jim were to lie, that would make him unethical, but not necessarily immoral.
Ethics is simply a list of accepted behaviors that reflect underlying moral values. However, in the presence of competing moral values, there is no ethical solution possible if the values are not prioritized. In the Bible, life is valued more highly than truth. That is why it is both ethical to lie in order to save the life of another and that is why it is unethical to tell the truth knowing you are condemning an innocent person to death.
The main problem with the areumgnt from the article you provided can be found in the second claim: the origin of evil is not the Creator but the creature’s freely choosing sin and selfishness. Why does he separate sin and evil? Is not the one intrinsic of the other? Wouldn’t you say there has to be evil in order to sin? If not, can we sin without it being evil?