Ben was raised on the island as a kid, he's got no perspective and is crazy. (like a fox) He knows where they are, and thinks its paradise compared to where he was. All those people will eventually die when they leave the island because that's what people do (except here).

Ben = no real world experience and total fear of life outside the island. Will also say ANYTHING to keep his spot on the totem pole.

Who is the oldest person on the island? How much has the island helped them to survive? Assuming it is locke, it would explain why he can get shot and not die, as it was the island that was keeping him alive anyway.

./shrug

that would also explain why he can hear jacob.