yes even though i have watched episode 1&2 and have the next 2 episodes to watch tonight

i am not gonna start discussing what has happening.. what i want to discuss is series 2.
remember in series 2 they wanted WALT so badly, like he was the answer.. so why let him go ? if i remember correctly it was to do with his comic book with the polar bear, and the polar bears obviously on the island.
and one another thing, the girl hurley had a thing with, why show her in the mental home with hurley and then kill her off, whats the relevance with that >?