You have to remeber the time frame. It was a week for us, but maybe only hours for the characters. I suspect that when Kate showed up and talked to Sun, she might have just been returning from her shift in the bunker. I'm not sure who was pushing the button during this episode, but it might have been Rose since all the other involved characters were seen wandering about. I think the bottle was only found the day before.
I agree, not much new on the Jin and Sun front; interesting but not really useful. I thought Sun's blind date not thinking she was into him at all was kind of silly. She'd given no indication that she was just playing along. I thought it was clever that orange was the color of love. Jin sees the girl in the orange dress, looks over his shoulder and BAM. Cute.
Those "Others" really went native.
Not a pair of shoes on any of them.
SPOILER
Now they're hyping an upcoming death again. I hate that shit. (I know who it is, by the way)