1. Well if you look at a certain way both are right. Shien turns blaster bolt defensive moves into strong offensive moves. That is the saber form Luke and Vader fight with. It's more offensive than defensive however.
2. Like Mothman said, it only refers to Sion, Nihilus, and Kreia
3. It refers to the movies.
4. Perhaps the Exile was lying to Nihilus to prevent him from trying to destroy the planet or maybe the Exile just didn't know there were any Jedi left on the planet.
5. The Unknown Regions to fight the true Sith.