2. It is apart of Ben con. To give Kate enough info that they will be leaving so it would be more easy to trust Juliet when she finds out they left her too.

5. Possible things to blow up with that amount of Dynamite

a) As mentioned by Cable the sonic fence.
b) The Barracks
c) The medical hatch Kate and Claire took her to
d) The thing the in which the cable leads to that was found by Sayid and Hugo. We still haven't seen what is connected to it.
e) New boobytraps

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