You've sort of hit on my own view of the end. It's weird, cause I read the comments from John Adams and I remember how I felt just two weeks ago where I had issues with all the same points he brings up.
From time to time when I log onto Facebook, I get a friend request from someone I went to high school with. Now the funny thing is that it almost doesn't really matter if we were good friends or just acquaintances, if we traveled in the same circle or different, liked each other or didnt like each other, etc. No matter the circumstances of the past, I almost inevitably feel really happy to see them and hear from them. The circumstances of our relationship (or lack thereof) in high school were completely irrelevant. What mattered most is that we were both THERE, that we both shared a common experience, and that now we were reuniting after twenty years. The significance was our common experience...that's what mattered most and that's what led to my feeling of happiness to see them today.
I think this is exactly why even though I very recently had many of the same issues that John Adams has today, this last episode was so beautifully done and it took me to a place where, just like seeing a classmate after 20 years, the circumstances just didn't matter. The shared bond was a beautiful thing, and when you reunite with someone after so long, it's a very emotional thing.
It was pretty clear that this finale wasn't some immediate segue from their lives on the island to the afterlife. For at least most of them, A LONG DAMN TIME had passed from the initial crash of the oceanic flight until the church reunion. When that happened, it's almost like it made the circumstances of the island irrelevant, or at least secondary, to their "awakenings" and the realization that it was the bond they established through the shared experience of the last six years (our time) that mattered most.