These websites/emails are excellent examples of a typical JW/607 apologist tactic. That tactic is to provide a particular interpretation of Bible verses and then explain how that interpretation fails unless 607 is correct. They want you to conclude that you can't believe the Bible unless you believe in 607.
Rather than try to reconcile the scriptures with the mountains of archaeological evidence favoring 587, these apologists take a hard-line fundamentalist view. Such an approach is similar to that of "young earth creationists" who say that Genesis teaches that God created the universe in six literal days. According to them, the Bible clearly describes six literal days--with "evenings' and "mornings"; thus anyone who tries to say the days not literal 24-hour days is contradicting scripture.
Now, even JWs don't follow such a literal interpretation of Genesis. Rather, they realize that there's indisputable scientific evidence that the earth is billions of years old and that there's been life of some sort for many millions of years. Thus, they take a less literal view of Genesis (arguing for a "creative day" that could be thousands or millions of years in length). Thus, they're able to attempt to rationalize science and the Bible--at least to some extent. But they're not able to rationalize archaeology and the Bible because it destroys their end-times timeline.
Sorry for the digression...So, when reading these 607 arguments, you need to keep two things in mind:
- The apologists accept 539 B.C. as an absolute date based on archaeology--but that same archaeology also supports 587. So, because of the apologists' theological interpretations, they accept 539, but not 587. Quite disingenuous if you ask me.
- The apologists are unable to produce a neo-Babylonian king list that supports 607.
Also, note the ad hominems and general bluster of the Third Witness site (from the first post in this thread). As another poster pointed out, he's putting words in the mouths of Ray Franz and C.O. Jonsson. Always be wary of books/websites that resort to these tactics. You may even want to point this out to your dad. At the very least, it should cause you to view the content of that site with skepticism.