mike i am going to try to answer your questions based on what i think.

1.) dharma was a research group trying to exploit the powers of the island.
2.) like all the other others.
3.) born with it.
5.) who knows, some people live longer they said. probably of old age. just like sawyer and all the people on the plane.
6.) you know what, i askd same question. maybe he found the something all the others didn't have.
7.) contract issues probably.
9.) black smoke was jacobs brother. he got transformed when he was dumped into the light.
10.) i dont think ben went into the church because he did bad bad things and was kinda scared.