[Locke.]

The actor of Walt aged too fast, they wrote him out of the show because of that. They orginally planned on explaining everything about him.

And The Others never wanted war with the 815'ers. Ethan was sent into the camp to find out who everyone was, ect. Then his mission was to get Claire so they could experiment on her because she was pregnant and they wanted an answer to the fertility problem. Ben (or Juliet) told Jack in season 3 that "Ethan acted alone, nobody was supposed to get hurt". And Goodwin went into the tail section survivors to do the same as Ethan, except he ended up wanting to recruit Ana-Lucia so stuck around. Eko killed two Others when they were taking the kids, they weren't harming anyone.