As to the theory that the lockdowns allow the island to be seen Jug, the hatch wasn't blown 2 months ago and that's when Ben found out about his tumor. If he could have somehow arranged a lockdown to leave the island (according to the theory) that would have been plenty of time. But in keeping with that idea, that would mean that the others would have to be in contact with the people in the hatch (ie Kelvin and Desmond) everytime that they needed supplies dropped. And if doesn't seem like they are in contact with them at all.
I do not believe that Kelvin had anything to do with the others. They are seperate groups of people, so I do not know if they knew when a lockdown would be. I think they got supplies the same way as Kelvin did, but just did not know exactly when. And if a box of mac and cheese can survive so can a video tape. They land with a parachute.
Just a new theory here, nothing I am completely embracing.