Make the Lime-Tamarind Sauce: In a small saucepan, combine the sugar, lime juice, tamarind paste, salt and paprika.
Over medium-high heat, bring to a boil, stirring frequently.
Continue boiling and stirring just until the sauce reduces slightly.
Set aside to cool.
Reserve.
Make the Garlic-Chili Sauce: In a small, non-reactive bowl, stir together the fish sauce, rice vinegar, water, sugar, cilantro, garlic and chilies.
Reserve.
For the noodles, put the rice noodles in a bowl filled with the cold water and leave them just until softened, no more than a few minutes.
Drain and reserve.
(This can be done several hours ahead).
About 30 minutes before serving, heat about 1 inch of the vegetable oil in a medium saucepan or wok over medium-high heat.
Add the tofu cubes and deep-fry until golden, 1 to 2 minutes.
Remove with a slotted spoon or wire skimmer, drain on paper towels, and set aside to cool.
Reserve.
In a small skillet, heat the butter over medium heat.
Cook the scrambled egg until it forms soft, moist curds.
Transfer to a plate and set aside to cool.
Chop coarsely and reserve.
Heat a wok over high heat.
Add the 2 tbsp peanut oil.
When it's almost smoking-hot, add the chilies, shallots, ginger, lemongrass, kaffir lime, chopped cilantro and shrimp; stir-fry until the shrimp gain pink color, about 2 minutes.
Add the noodles, half of the bean sprouts, the fried tofu, the scrambled egg, and both sauces.
Continue stir-frying until the noodles have separated, heated through, and are glazed with the sauce and mixed with the other ingredients, 1 to 2 minutes more.
Transfer the noodles to a serving plate.
Top with the remaining bean sprouts, cilantro sprigs, green onions and peanuts.
Serve with lime wedges to squeeze over the noodles.