The Freighties say that the helicopter was struck by lightening which caused their electrical equipment to malfunction.....however every craft, ship, vessel that gets near this island crashes...

Was the crash really due to the lightening this time? Did the Freighties know that something like this might happen, would explain why they were all wearing parachutes and those GPS things.

Once they take off in the helicopter again to get off the island, will it let them leave? Desmond's boat came right back....

They put on the parachutes and the GPS locators when they realized that the helicopter was going down.