Crab Dribble by definition, is not a travel, according to Jalen Rose. LeBron James version of Crab Dribble = travel.
All the super stars (ahem, including Brandon Roy) get away with three steps all the time. Lebron and Wade are probably the worst, Kobe gets his share. It's like as long as you are making a move to the basket anymore, it doesn't matter how many steps you take. I saw one of Lebron's moves where he jump stopped, and took three more steps and no travel was called.