LOST- Recap: Ben can control the smoke monster?

Okay, so I wrote this last week, but then never hit publish apparently. So very sorry folks.

Synopsis:

Doctor from the freighter washes up on the shore with a slit neck.

The Commandos Attack, kill some miscellaneous people and kill Alex, dead.
Before Alex is killed, we learn that Ben did steal her as a baby from Rousseau, not that Ben and Rousseau were lovers.

Ben releases smokey who kills the commandos.

Dan, the scientist gets a telegraph working, and communicates with the boat, but then lies to the losties about what is going on, luckily Bernard knows Morse code and tells them the truth…we then learn that they had no intention of getting them off the island.

Sayid marries Nadia in the future, but she is murdered.
Sayid starts working for Ben after learning that Widmore ordered Nadia's murder.

Ben can get on and off the island with a sailboat and a heading to Fiji.

Ben tells Widmore he is going to kill Penny in exchange for Alex’s death.

Widmore tells Ben that it is his island and he wants it back, Ben says he'll never find it.

Sawyer and Claire leave Locke and Ben and head back for the beach, Locke and Ben keep Hurley, they need him to help them find the cabin (Jacob.)

Jack has a stomach ache.

Okay, so here are some questions:

How does Ben control the smoke monster? How can he get information on everybody? (remember he was able to relay all the personal specs on the commando before he kills Alex.)
How is it that Ben is able to sail off the island, but nobody else can?
Why was the island always Widmore's? Was Dharma always his?
Does Ben work for Widmore and has become disillusioned? Or does Ben just know who Widmore is? Why does Widmore allow Ben to live?