All good theories.
I agree with the theory that the reason Ben is beat up is b/c when he said he had a promise to fulfill (or something to that effect), it's b/c his promise was to Widmore. Widmore had Alex killed so Ben killed Penny. After all, he WAS on the boatyard beat up & bloody when he called Jack to tell him to pick up Locke.
Next week's episode looks awesome! Locke is alive? He was talking to the agent that had Sayid. I can't wait for the Jin/Sun reunion.
Hurley brought a guitar on board. Odd isn't it? Maybe Charlie was the one who told him to take it since Charlie had a guitar with him when he was on the plane the first time.