Preheat oven to 550 degrees F (288 C), or your highest oven setting.
Heat 2 teaspoons oil in a skillet over medium high heat until hot. Add shrimp, lightly sprinkle with salt and pepper. Cook and stir until the surface turns opaque but the inside is not cooked through. Transfer to a plate.
Dust a pizza baking tray or pizza stone with cornmeal or semolina flour.
Place the pizza dough on a lightly dusted surface. Divide the dough into two pieces for making two medium-size pizzas. Shape the dough into a ball and gently press it into a round disk. Then pick up the dough with your hands and hold onto the edge. Slowly rotate the dough and allow gravity to stretch it out. If the dough springs back too often, place it back onto the work surface and let it rest for 5 to 10 minutes before working on it again.
Once the dough reaches the thickness you prefer, place it onto the baking tray. Bake until the dough becomes just firm but not browned, 5 to 7 minutes (*footnote 3).
Take out the pizza crust. Brush the edge with a thin layer of oil. Brush half of the wasabi mayo and spread with a thin layer of crab meat. Scatter half of the cheese over. Then top with shrimps, onion, pepper, and pineapple. Lightly sprinkle a pinch of salt and ground black pepper. Return the pizza back to the oven. Bake for another 5 to 6 minutes, or until the cheese melts.
Take out the pizza and let rest for 2 to 3 minutes to let the cheese set, then slice and serve hot (footnote 4).