My initial thoughts on the Lost finale

I felt a little letdown by the season finale of Lost. But after thinking about it for a while, I realize that this ending was the only one that would have made sense.  Lost was all about questions for so long, and they did such a good job of making us want answers, that I think it would have been impossible to explain everything and still have the show make sense.
 
After the show, my wife and I were talking about it, and she pointed out that this wasn’t such a bad ending as everyone was finally happy. None of them, except maybe Locke, was really happy about being on the Island in the first place.
 
It just drives me crazy that I spent the last six years asking “Why did this happen?” and “What does this mean?” and “Whoa, what was that?” only to find out that none of it happened, and therefore we don’t need answers.  I’m basing this off the assumption that they all died in the plane crash, which was never explicitly stated. Although the last scene of the episode made it pretty clear.
 
In the beginning of the series, we talked about the possibility that they were all dead and in purgatory. But that possibility left my mind after awhile as things just got so detailed and people came and went from the Island.
 
So, if this was purgatory, how do you explain all the other people who came to the Island? I’m thinking of people like Lapidus, Richard, Miles, the Others, Widmore and the Dharma folk. There was no closure there for me.
 
And why did some people, like Mile’s dad and Anna Lucia appear in the flash-sideways, but never “remembered?” And there was a ton of people missing from the reunion. I mean where were Michael and Walt? Did they have their own mini-reunion?
 
And more importantly, what TV show am I going to look forward to watching each week, now that Lost is over?
 
I guess I was expecting real answers to all my questions, but in true Lost fashion, I got more questions.