First of all, great ideas and theories all :)

I've been thinking about this lately, and I'm trying to focus on the big picture and the fact we know, and trying to keep it simple.

So here is what we know for sure from the show:

a)Existance is cyclical. "Life here began out there" and "what has happened before will happen again" deal.

b) The Temple of Five, which was built by the 13th tribe during their journey to earth, was constructed 4000 years prior to the Fall of the 12 Colonies. And Battlestar Wiki says the 13th tribe left 2000 years before the Exodus of the 12 tribes from Kobol. So the span of time from the journey of the 13th Tribe, to the current journey of the Galactica in search of Earth, is 4000 years, and its'the same journey. So we can say that a cycle of existance is 4000 years long approximately. So the first cylon war and the events of the past 50 or so years are negligible in terms of the big picture.

Ok sorry gotta cut this short, see I think the key to everything depends a lot on who or what the Lords of Kobol are. They are crucial to understanding the big picture. We must understand Kobol and it's Lords, which I see as the beginning of the cycle, and finding Earth as the end of the cycle.

So the cycle could be something like this:

a)Paradise-like existance on Kobol
b) Introduction of sin, either by a "jealous Lord of Kobol" hungry for power, or within the people themselves.
c)War on Kobol, exodus of the 13th Tribe
d)Exodus of the 12 Tribes and founding of the 12 COlonies
e)Creation of the cylons
f)Destruction of the 12 colonies by the Cylons, exodus of humanity towards Earth
g)Human-Cylon, Human-Human, Cylon-Cylon Wars
h)Enlightment and Revelations arrived at through terrible loss and suffering.

Possible end of cycle outcomes at Earth:

a)Unification of Humans and Cylons, inter-breeding, upon arrival on Earth, and integration with the 13th Tribe already there. New generation of Cylon-Human babies born, and 13th Tribe is already filled with this generation of hybrids.

b)Humans and Cylons are the same. Humans are just Cylons programmed to think they are human. 13th Tribe wipes out the Cylons, and it's 100% back to humans again, but bakc to sticks and stones with no technology aftera big war on Earth.

Beginning of new cycle. Earth becomes the new Kobol. Whether filled with new generation of Cylon-Human hybrids, or pure humans who won the war.

I guess we really have to wait and find out, cause some of these theories really sound whacky lol.

I'm sure RDM is 20 steps ahead of our thinking and has a much better explanation to it all.