Good questions, except #2 and maybe #3, I think. With regard to question #2, logical order and chronological order are two different things. It would be perfectly logical, for example, to rank events in order of their importance, but that would not necessarily be chronological order. The fact that both words contain "logical" doesn't imply that they mean the same thing. I don't see any conflict between Luke's opening statement and the passage you cite from the Insight book.
As far as Rahab and Ruth, there is no implication in the Bible or in WTS literature that their presence "corrupted" the Messianic lineage. They were proselytes to the worship of YHWH, which carried a different status than that of the "alien resident." The proselyte was regarded as essentially having become a Jew; male proselytes would be circumcised, proselytes could engage in worship with the Israelites, even attending the Temple. Wikipedia (granted, not always the most scholarly source, but good as a quick reference) makes the following distinction:
There are two kinds of proselytes in Rabbinic Judaism:
- Ger tzedek (righteous proselytes, proselytes of righteousness, religious proselyte, devout proselyte)
- Ger toshav (resident proselyte, proselytes of the gate, limited proselyte, half-proselyte)
A righteous proselyte is a Gentile who has converted to Judaism, is bound to all the doctrines and precepts of the Jewish economy, and is considered a full member of the Jewish people. They are to be circumcised as adults (different from Brit milah) and immersed in a mikvah should they wish to eat of the Passover sacrifice.
A gate proselyte [5] is a "resident alien" who lives in the Land of Israel and follows some of the customs. They are not required to be circumcised nor to comply with the whole of the Torah. They are bound only to conform to the seven precepts of Noah, the Noahide Laws: do not worship idols, do not blaspheme God's name, do not murder, do not commit immoral sexual acts, do not steal, do not tear the limb from a living animal, and do not fail to establish courts of justice to be assured of a place in the world to come.
If Rahab and Ruth were of the first category, which I would assume was the case, it hardly seems that their presence in the Messianic line would be seen as a corrupting influence. In fact, it was not, because King David was also descended from these women, and no Jew would have questioned his credentials. Obviously, Rahab and Ruth were regarded as full members of the nation of Israel after their conversion.
That said, the other questions are excellent ones, and I'll be interested to see if any active JWs have a response to them.