User blog comment:SuicidalSkydiver/Kuma a revolutionary?/@comment-68.43.155.67-20100605233911

That pretty much explains why he sent the straw hats flying to different places, because he probably sent them to train. He obviously knows that Luffy is Dragon's son, and knows that Luffy's intentions have goodness in them, and he probably realizes that Luffy should be the future Pirate King.