Here's a rule of engagement with which I'm sure you'll agree: proposing a possible interpretation is of very little consequence. To get my attention, an interpretation will have to demonstrate support from a preponderance of evidence.
Another point: the burden of proof, in this discussion, is on you, as your goal seems to be for me to take the arguments of documentary hypothesis seriously. Should, therefore, documentary arguments present themselves as nothing more than clever possibilities which lack compelling evidence, then you've failed. If I were trying to convince you of the authenticity of MT (Masoretic Text) and the Divine revelation, then the proverbial shoe would be on the proverbial other foot.
Deductions drawn from stylistic differences (especially variations in the usage of God's names) are a perfect case in point. Critics maintain that the existence of such differences in the Bible text implies that there was more than one author (each one writing in a different style). Perhaps. But the differences could as easily (or even more easily) be explained by positing a single author with multiple messages. Perhaps, too (as has been traditional Judaism's approach since at least the time of the Talmud), the variations are also a kind of code meant to efficiently convey (in a concise manner for which the Five Books are already famous) different manifestations of God's terrestrial involvement (example: His attribute of Justice vs. His attribute of Mercy).
At best (AT BEST!) then, the result is a draw (in other words, we're faced with two possible explanations for the text's anomalies between which there is no obvious way to judge). Hardly, however, evidence for multiple documents.
Regarding the essay you sent me in which Moshe was described in the third person (here's the relevant text from that essay: "that it repeatedly refers to Moshe [Moses] as 'across the Jordan' from the viewpoint of the narrator, describes his death and in a manner that implies it was long ago from the perspective of the author"). That's nothing serious. We've all read autobiographies which use the third person from time to time, right? Think: if the entire Torah really was written down by Moshe himself after being dictated by God (which is, after all, the Bible's core internal claim, see Deut. 31; 24), would a bit of third person narrative be out of place? Of course not. It's a literary style (adding the capacity for yet another layer of meaning). Your "later author" scenario is, like thousands of other guesses, possible (although jarringly extraneous to the text), but hardly compelling.
Reference to Edomite kings who hadn't yet been born (relevant text: "it includes a list of Edomite Kings (Gen 36) that reigned long after his time")? Oh come on! The Five Books (according to our account - which is, after all, the current subject of our debate) are a work of prophecy: predicting stuff is what prophets do, you know! If God was dictating, it should hardly be surprising that there's inside knowledge. Again, your scenario is certainly no better than the traditional version.
The flood story is "schizophrenic" (the essay had raised some well-known textual complexities in the flood narrative and "demonstrated" that the words of a number of authors must have been intermingled throughout)? Have you seen the works of Rashi, Nachmanides, Ibn Ezra and Abarbanel on the subject? It is complex (but so is anything worth studying) and there is surely more than one approach, but there need be nothing "schizophrenic" about its intelligent reading. Again: given that there are a number of perfectly coherent and structured interpretative systems (and reasonable explanations for their order of presentation - see especially Abarbanel), it is at least as likely that the complexity of the text's dating method and general narrative is both intentional and cohesive. Rearranging the text more "attractively" doesn't prove (to any reasonable standard of proof) that that's the true state of the original document.
It's similarly weak to claim that stylistic differences like "story-telling" vs. "obsessive details" bespeak multiple authors any more than comparisons between my friendly correspondence, rhetoric and the prose I employ while writing to the contractor who built my home extension suggest that I'm somehow internally conflicted. I write differently to different purpose. So, I'm sure, do you.
An anthropomorphic or non-anthropomorphic god and the first two chapters of Genesis are just more of the same. Again: they could be read your way (among many others), but the fact that the Talmud, Midrash and classical scholars like Rashi anticipated virtually every argument and presented their own approach(es), means that your reading is just one of a collection. Go prove yours is historically accurate.
One more thought: let's say that there really is no rational explanation for the structure and style of the text (a possibility which, by no means, do I accept). Does even that prove your point? Is it not also within the realm of the possible that God wrote it to be unintelligible? Knowing what I do about the quality of books written by committees (especially virtual committees), I would suspect that even that scenario is intellectually preferable to multiple authorship!
Now, as to the textual reliability of MT (Masoretic Text - the version of the Torah universally accepted by traditional Jews), I must provide an introduction.
First, I'll concentrate exclusively on the Five Books as it is on that text that Judaism lives or dies. If it can be proven that there are multiple (and mortal) authors, then Deut. 31; 24 is a lie and the entire book and the Torah lifestyle that springs from it are fraudulent; having no objective value. The textual status of the rest of the Bible is, I believe, a somewhat different issue.
Second. Do I claim all of the Torah scrolls used through the ages are absolutely identical? No. Nineteenth Century Rabbi Akiva Eiger, in his glosses to Tractate Shabbos, identifies at least a dozen instances where it's clear that the Torah used by Rashi was different than ours. The differences are all very minor and don't affect the reading in the slightest, but there are differences. Even in modern scrolls, there are famous (though minor) variations between those used by Ashkenazim and Sefardim.
The Rambam, contrary to popular understanding, never wrote that our Torah scrolls are letter-perfect copies of the one Moshe gave us. He wrote only that the entire corpus of the Torah (including the laws of the Oral Law) are a direct and accurate account of the Torah that Moshe received.
Now on to other things. Is it possible that there are significant variations and errors in our text? I believe that's highly unlikely, but I don't believe my reasons for that belief are connected to this discussion so I'll leave them for another time.
Is there any evidence that there are significant variations and errors in our text? Do variations in the Qumran and LXX versions (and any proposed correlations between then) compel me to consider the possibility? Frankly, the textual variations I've seen from the flood story aren't impressive. They could very easily have been the result of lazy copy boys (the type who, in Yiddish, we would dismiss with the title "der bocher hazetzer") and the variations might have had nothing at all to do with whatever original Hebrew was used. By the way, I'm sure you're aware of the Talmudic version of the LXX creation in which quite a few explicit, conscious mis-translations were included for political reasons (to avoid anticipated misunderstandings). So, according to tradition, LXX didn't even start off as a particularly accurate version.
But far closer to the point, the holy grail of "higher" criticism isn't simply to demonstrate that there could have been adjustments to textual fragments, but that there is evidence of a wholesale fabrication of the entire Torah over centuries. In other words, that, for instance, the entire book of Deuteronomy was added centuries after its internal orientation claims it was written and publicized. There is nothing at all in any of the scenarios you've presented to me that could account for that level of fraud.
To be thorough, I would suggest that you read Dr. David Gottlieb's Living Up to the Truth - specifically the chapter called "Revelation and Miracles". He rigorously discusses the practical improbability of such a fraud.
You will probably also want to read the sharp attacks against his work that he's allowed to be posted along with his responses.
In any case, I look forward to your response.
None has been forthcoming.