Guys, these episodes have been awesome! That opening scene on EP4 was fucking fantastic, I can't get over how well this show is animated.
The thing on Jinorah's astral projection, I think she was deceiving Kai a bit, saying it was an airbender technique. She said it in a way that was trying to gloss over it. I don't think she wanted to freak him out any more, so she went for the most convenient explanation.
Anyways, Lin obviously has some legit reason for being so hostile, hopefully we find out sooner than later. Also, Book 4 definitely needs to be aired 2 episodes back to back. Its the perfect amount of time to spend with the show each week.
Yeah they are so awesome. I'm really happy that this season has been this great. Falling back in love with it (even if it's not perfect).