I think you may not understand translation work on a professional level and how translations are regarded. There is no such thing in most cases of a single translation judged to be the most accurate. In translating Sumerian, Akkadian, Babylonian, Egyptian, or any of the other ancient languages into modern English (or another Western language), the translator has a fair amount of play because of the much-larger vocabulary of modern languages. In the end, regardless of the subtleties of modern vocabulary employed, the sense and meaning of the translation comes out the same. A translation that varies wildly from the greater body of professional literature means almost certainly that the translator is flawed and/or his translation is incorrect. No two ways about it.
Sitchin did not really translate any of this stuff himself. He drew from the greater body of professional literature and invented his own meanings to suit his personal agenda. He comments on a wide variety of traditions and cultures and the textual material they left behind, so anyone who honestly believes that Sitchin possessed a working command of the numerous different languages expressed in cuneiform as well as ancient Egyptian, as well as Aramaic, and as well as Hebrew, has some definite problems with naiveté and gullibility. I cannot even think of a past or present professional scholar who could have or does possess a working knowledge of that many ancient languages and scripts. It's not realistic in the first place.
Some of the stuff Sitchin uses comes from Babylon, some from Akkad, and some even from Sumer. There are only a scant handful of places in the world where a student can learn Sumerian today, so it would be quite comical to assume that Sitchin somehow knew the ancient language, himself.
Understand that Michael Heiser is not "piggybacking" off of Sitchin. Heiser's website is only a lark on his part, a side hobby. The man is a professional scholar and linguist with a published body of literature. If you actually did read through Heiser's website and especially the topic-specific papers you can download, and somehow think that he is merely criticizing Sitchin, you must not have read too carefully. Time and again Heiser picks a specific example which Sitchin misrepresented (e.g., the meaning of Anunnaki, the meaning of Nephilim, the actual meaning of Nibiru, the correct meaning and interpretation of Elohim, the proper analysis and interpretation of the VA243 cylinder seal) and explains in very clear terms exactly why Sitchin's take on such things was misleading and plainly incorrect. Heiser explains the orthodox position and, importantly, cites his work—something Sitchin never properly did in his own books.
Sitchin was at best disingenuous. At worst, outright dishonest for the sake of personal monetary profit and notoriety. In other words, Sitchin was simply typical of the fringe authors who churn out endless books of no historical or scientific merit.
I like the first half of your post but i would still not agree with a few points you made.
Sitchin is not famous or embraced only fringe proponents though he might have spawned quite a few.
I am happy that you acknowledge that there is a lot of scope for the translator to use his own interpretation when trying to translate ancient scripts. After doing the translation he has to form a consensus amongst the monopoly club and there are more ways to build consensus other then merit.
Sitchin doesn't seem like a person just after money as there are many other ways to do it,nor do i feel that Sitchin's game plan ever was to invent stories and sell books.I don't think Sitchin ever was confident that so many people would buy his books when he first wrote them.As a proof to my statement i would like to point out that there are thousands of fringe proponents writing books,but not all are that famous.
I never exclude the chance of the majority being wrong and the minority being right (i don't discard the underdog).So even if a professional body does disagree with a translation doesn't mean it is wrong.I would not put down any alternative when the primary theory is based mostly on consensus and not empirical fact.
Your comments on Heiser and his work only strengthen my argument that his work and fame only come by denying and trying to disprove word meanings or interpretations used by Sitchin.Also Heiser doesn't need funds as his work is sponcered.
And again i would like to point out that Sitchin's version is not so bad,but the major beef people have with him is due to the fact that he claims it to be actual events and not just myths.