Par boil pork bones by adding bones to a 8qt pot, and covering them with cold water (almost to the top). Let the bones come to a boil, then cook for about 10-15 minutes to remove the impurities. Drain and rinse the bones in a colander with cold running water.
Wash the pot, add the bones and fill with cold water again (almost to the top). Turn heat to high, when it reaches a boil, reduce heat to medium low and simmer. Add onion, ginger, and rock sugar. Allow broth to simmer for about 2 hours.
Meanwhile add shrimp, crab, crab paste, eggs, shrimp paste, minced garlic, and shallots to a food processor. Pulse for about a minute so that the mixture starts to stick together but is still lumpy. Place aside and refrigerate.
After the soup has simmered for about two hours, add the tomatoes into the broth and bring back to a boil.
Take out the shrimp/crab mixture and scoop a spoonful into the broth, one at a time to form "meatballs." Boil for another 20-25 minutes so all the flavors marry. Add 1 Tbs fish sauce, or more depending on taste desired.
Add the tofu puffs to the soup and simmer.
Boil rice noodles, strain, and set aside. Add rice noodles to a bowl, top with the boiling soup, some shrimp/crab balls and tofu puffs. Top with sliced onion, chopped green onion, and cilantro.
Serve with bean sprouts, mint leaves, jalapeño peppers, lime, and Sriracha.