PURPOSE

In the mish-mash of people reconstituting new groups like a single cell organism ready to divide into two, a basic question of purpose needs to be addressed:

What purpose does/did Jacob provide the Island? "Protection," is the answer, but from what?

What purpose does/did MIB provide the Island? "A rival," is the answer, but why?

What purpose does/did the Others provide the Island? We really don't know why there is a "native" band of Hostiles living on an uncharted, supernatural island in the middle of the Pacific.

What purpose does/did the Others "leader" provide? "To speak to/through Jacob," is the answer, but why is there the need to follow Jacob's instructions?

What purpose does/did outsiders like 815 survivors provide the Island? "Candidates," appears to be the answer, but why does forcing people to the island to succeed Jacob serve the interests of the Island, the Candidates, or the Others?

What purpose did the Dharma Initiative provide the Island when Jacob was supposed to "protect it" from outsiders? "More candidates?"

Why does Jacob want "candidates" to replace him? What is his purpose or motivation to leave?

Why does MIB want to "kill" Jacob? Why can't MIB just transform and leave? Why must he destroy Jacob first?

Are both "trapped" on the Island for eternity? Is there whole purpose, or existence, a way to break the bonds that the Island (realm) has upon them?
Is the solution that Jacob or MIB cannot "leave" or be free unless they are replaced by a qualified "candidate?" After hundreds of years, you would think if they really wanted off the Island, a candidate(s) would be appointed and case closed. That begs the point that the concept of a "candidate" is a ruse, a red herring. Candidates must serve a different purpose than being courted as replacements for the Island's apparent supernatural entities.