JanH,
It is true that the argument from evil which generally demolishes classic theism does not help to disprove a less-than-good deity or even a slightly incometent deity.
Yes, that's where I was going with the argument. It's doesn't take a rocket scientist to read the Bible and see many episodes of morality clearly violated by God. Indeed, if the Bible is really the "Word of God," then God is getting away with murder--a concept Bible believers skirt with various scriptures or circular arguments. You correctly point out the "evil deity" theory doesn't disprove the deity theory, however, I wasn't going there.
Finally, there is no reason to believe that such a deity, or any deity, exists. Theism exists only as a nostalgic throwback to primitive times, when people needed supernatural beliefs to understand nature. Today we should not need to believe in ghosts, fairies or deities, since there is no evidence for such things.
Jungian theory might suggest the deity concept comes from the "Collective Unconscious," but there isn't much evidence in that bowl of pudding either. However, it's useful in explaining how some notions are carried on through time. Larc has a Ph.D in this field, perhaps he has some thoughts on Jung's idea.
Maybe it's a JW-carry over, but I like the theory of an all-knowing deity. Just liking the concept doesn't make it so, and the biblical deity(ies) is not creditable (to me). Yet I come across things from time to time that's thought provoking, and feels like a spiritual read (or something of that sort). That doesn't prove anything, but it's fun exploring antique shops; walking out empty-handed isn't all bad either.