1. For Juliette
2. He wants Locke to 'save' Kate eventually, so Kate needs to trust him
3. no idea
4. the kids were frightened with the Others, and asked that Cindy, who was nice to them on the plane, join them.
5. Danielle is Smokey, and can't pass through the sonic fence in smoke form, so she's going to blow up the whole damn fence.