For the dipping sauce: Combine 1/2 cup (125ml) water, the sugar, vinegar, fish sauce, ginger, soy sauce, garlic and lime juice in a small saucepan. Bring to a simmer over medium heat and cook until it thickens a bit, about 5 minutes. Let cool. For the thin omelet: Sprinkle the eggs with salt and pepper. Heat a nonstick skillet over medium-low heat and coat with a small amount of oil. Use a paper towel to spread it around and wipe up any excess oil. Add a little of the beaten egg and rapidly swirl it around until it coats the bottom. Cook over low heat just until the egg is set, 15 to 30 seconds. It's done when the edges are dry and the top is just about cooked. Loosen up the edges of the omelet with a spatula, then flip the pan upside down onto a plate. The omelet should flop out like a crepe. Continue with the remaining egg. Roll up the omelets and cut into thin strips. Set aside. For the spring rolls: Remove the crabmeat from the shells. (You can reserve the shells in a freezer bag for making stock). Lay a spring roll wrapper on a work surface so you have a diamond shape. Arrange some scallions, carrot, celery and kimchi in a rectangle in the center of the diamond. Add some of the omelet and spoon over some kimchi. Top with a spoonful of crabmeat and some cilantro. Dip your finger in water and spread a small amount around the edge of the wrapper. Fold in the two sides of the wrapper, then fold the top down and the bottom up to enclose the filling. Cover each roll with damp paper towels as you finish. Heat the canola oil in a deep fryer to 375 degrees F. Fry the spring rolls, turning them once or twice, until golden and crisp. Transfer to paper towels to drain. Serve the spring rolls with the dipping sauce.
Dissolve the salt in 12 cups (3 liters) cold water. Add the cabbage and refrigerate for 4 hours. Rinse the cabbage thoroughly under cold running water at least 3 times. Pat dry. Bring 1 1/2 cups (375ml) water to a simmer in a skillet over medium-high heat. Add the flour and whisk for 3 minutes. Add the sugar and continue to cook, whisking, for 1 minute more. Pulse the red pepper powder, garlic, ginger, lemongrass and onion in a food processor. Add the flour mixture and pulse to combine. Set the kimchi paste aside. Combine the brined cabbage, chives, fish sauce, soy sauce, scallions and cucumbers in a large bowl. Stir in the kimchi paste. Refrigerate until ready to use. You can eat the kimchi fresh, right after making it, or wait 24 hours until it has fermented.