The woman from "Sabbath Queen" is Death of the Endless.
David will become king because Cross pulled strings.Now that David's loyalty to Silas is broken, or at least frayed, and Jack has tried to back out of his deal, Cross will see David as a better means to topple Silas. He'll get David out of prison and eventually get him made king. David is too honorable to knowingly go along with a coup, but Cross could probably manage it anyway. Though I do wonder what Reverend Samuels will think of it all...
David is...The form chosen by Shinji Ikari in an attempt to find a functional family. He thought that, if he was not dirt poor, he could have a nice life and so, all events are plan him to achieve this goal. He might have gained some fame and fortune, but his fortune and sense with choosing father figures still needs work. My bets are that Gendo was revived as Silas, thus he desired revenge for his time as tang. Yui was made into the queen. Jack is really Kaworu Nagisa, who sought Shinji again, but...well, naivete is expectable after a long time dead/whatever. Asuka/Rei is David's sweetheart, who was made less rough or more sociable, respectively
The entire series is set After the EndThis troper has an acquaintance who missed the first few episodes, but her father, in his attempts to fill her in on what she missed, apparently interpreted Gilboa and Gath as After the End nations in the former United States. She couldn't give me many details on this theory, the whole thing was rather confusing...but in a way it's almost plausible. Perhaps something happened that tore the nation (even the world...if not for Austeria, I wouldn't even consider this aspect, though) apart and killed millions of people but left the land and cities relatively unscathed. Gilboa formed in perhaps what was once New England and Mid-Atlantic states, since Shiloh is pretty obviously near-identical to New York City, while Gath might be in the south or midwest somewhere, or maybe even the former Canada for all we know. As a theory, it doesn't explain everything, but it does make some sense...
Andrew and Michelle were going to be betrothed before Michelle's cancer (and Andrew's exile).
A butterfly flapped its wings and things ended up very differently in America.