Bart Erhman's odd Job

Ehrman begins his overview of Job with the claim that "the book [of Job] as it has come down to us today is the product of at least two different authors" and these "two sources... have been spliced together to make the final product" ([God's Problem], p. 162; 163 all references, unless otherwise noted, are from this source). One may wonder just how he managed to deduce this. Perhaps he unearthed copies of the original, separate stories? Don't be silly! Rather, like another practitioner of this craft, Bernard D. Muller [1] (who's work I've commented on on TheologyWeb, although I'm planning on running a more thorough rebuttal later in this blog) and in the finest tradition of "skepticism masquerading as scholarship", he attempts to "to flag out the 'smoking guns'"- even when the only trace of smoke exists in the imagination of the skeptic. But that is merely assertion, worthless unless I can show the reasons for his claim of dual authorship stand on less than solid ground.  As far as I can tell, here is the entire list of his claims (pp. 162-164, 167):

1. "[In] the prose narrative[,] Job [displays] patient endurance under duress[, but in] the poetic dialogues... Job is not patient but defiant" (= "in the prose [Job] is a patient sufferer; in the poetry he is thoroughly defiant and anything but patient");
2. "[In] the prose narrative[,] Job['s] patien[ce] is rewarded by God[, while in] the poetic dialogues... God does not reward the one he has made to suffer but overpowers him and grinds him into submission" (= Job " is commended in the prose but rebuked in the poetry");
3. "The writing styles are different between these two genres";
4. "[T]he names for the divine being are different in the prose (where the name Yahweh is used) and the poetry (where the divinity is named El, Eloah, and Shaddai)";
5. "[T]he prose folktale indicates that God deals with his people according to their merit, whereas the entire point of the poetry is that he does not do that- and is not bound to do so";
6. "[I]n the prose narrative, suffering comes as a test of faith; in the poetry, suffering remains a mystery that cannot be fathomed or explained"; and,
7. "It is obvious that a bit of the folktale was lost in the process of combining it with the poetic dialogues, for when it resumes, God indicates that he is angry with the three friends for what they have said, in contrast to what Job has said. This cannot very well be a reference to what the friends and Job said in the poetic dialogues, because there it is the friends who defend God and Job who accuses him. And so a portion of the folktale must have been cut off when the poetic dialogues were added. What the friends said that offended God cannot be known".

Item 1: Good (five stages of) grief!  Even if Elisabeth Kübler-Ross' "idea of 'stages' oversimplifies a complex experience" Job provides near textbook examples of bargaining ("maybe if I say nice things about God, we can get this over quickly"?) in the prose and then anger ("Well, if God's not going to cure me, I'm going to stop saying good things about Him", which wouldn't be too surprising when the bargaining didn't work) in the poetry. In short, Ehrman fails to notice that some time has passed between Job's mood shift.
Item 2: And what happens between the rebuke and the commendation? Job repents, which may have led to the latter. Also, the rebuke addresses only Job's response while the commendation addresses that of his friends as well ("Eliphaz the Temanite..., [thou] and thy two friends... have not spoken of me the thing that is right, as my servant Job hath" Job 42:7). Therefore, this may be God's way of saying that while Job isn't entirely correct (thus the rebuke), he is closer to being right than his friends were (thus the commendation).
Item 3: I'm sure a single writer would never have thought of using different writing styles for contrast. This is one of those objections that are so blindingly simple to refute one has to wonder why it was raised in the first place.
Item 4: Again, contrast, this time between a stately God attending His court and a boisterous God that speaks from a whirlwind.
Item 5: This is simply false, as God's granting permission to Satan to do what he wants to Job, the stealing of the oxen, donkeys, and camels, the deaths of his children, God's granting permission to Satan a second time, and the start of Job's afflictions all occur in the alleged prose folktale. One would be hard pressed to claim these as examples of "God deal[ing] with his people according to their merit".
Item 6: While God's response to Job may seem incomprehensible to us, it would appear that Job understood it. Therefore, I would dispute Ehrman's claim that "in the poetry, suffering remains a mystery that cannot be fathomed or explained" as being only partially correct. That is, it may have been true during Job's affliction, but not afterward. Another mistake I believe Ehrman is making here is trying to universalize what was not meant to be universalized. The lesson I think we should take from Job is that even if we don't know the exact cause of a particular instance of suffering (although, as I've written before, we can know why suffering in general occurs), one should think twice before questioning God's wisdom. (Another lesson might be that it's easy to say that God punishes only the guilty when one isn't suffering).
Item 7: I think what the friends said that could have offended God can be known and, oddly enough, Ehrman supplies the answer when he writes: "there are obvious problems with [the suffering comes from God as punishment for sin] point of view, especially if it is generalized into some kind of universal principle" (p. 54).  Evidently, when Ehrman summarizes their arguments as follows: "Job is guilty, he should repent, and if he does so, God will relent and return him to his favor. If he refuses, he is simply showing his recalcitrance and willfulness before the God who punishes those who deserve it" (p. 175), he forgot that earlier he had "stress[ed] that the prophets themselves never state this as a universal principle, as a way of explaining every instance of suffering" (p. 53) as this is exactly what the three friends are trying to do (whether the friends got this idea from the prophets or somewhere else).

[1] This should not be read as implying that Ehrman endorses, or has even read, Muller's work, but rather that the two employ similar methodology.