Maui isn't set up well for parkour. It's just not that paved, and the man-made obstacles are a bit spread out. After a couple months of training, you'll either move on to free running and all the flips, or Methode Naturelle and run around in the woods. Maui has tons of great MN places.
Do you mean somewhere between Paia and Hana for north shore? North shore gets the winter waves. Today the north shore waves are 0-1' by Hawaiian measurement, or 0-2' faces. Good day for windsurfing or snorkeling. During the winter, north shore waves get BIG... 6-8' faces are pretty common, and at places like Jaws/ Peahi, it can get up to 70' faces - one of the biggest surfing waves in the world.