They aren't going to give too many detailed explanations to many things. There was an interview they did a while back with the lead writer/producer in which he talked about how in Star Wars, no one really questioned what the "Force" was, they took the simple explanation that Obi Wan gave to Luke (...the one where he says something like "it binds everythig in the universe") and no one really ever thought twice about it. And this writer/producer thought they cheapened the Force when they tried to provide further details in Phantom Menace when Qui Gon talked about "midichlorians". The problem with this is that Star Wars didn't provide 100 questions every movie (and, it was a movie, not a TV show which can allow for a longer plot and story).
So we aren't going to get real explanations to most things. Richard doesn't age because "jacob wanted it that way" is probably the explanation we'll get". From a character standpoint, what we're seeing more finality or resolution.....people are either changing or remaining the same. I expect some nice little rant/monologue/dialogue from some character (probably Jacob) which will probably be directed to the audience more than whomever he's talking to, about "what's important" to try to get the audience off the fixation with the "why's" of the show and on the "who's" of the show...but they're running out of time.
