Heat water and soak rice noodles, according to package directions, then drain and rinse in cold water to stop cooking (do not overcook noodles, as they are more delicate than wheat noodles). Drizzle lightly with vegetable oil to keep from sticking and set aside. In a small bowl, combine fish sauce, brown sugar, tamari, hot sauce and lime juice and set aside. In a large wok or skillet over med-high heat, add 2 T of vegetable oil. When oil is hot and shimmering, carefully add shrimp all at once (it will likely flare up briefly). Sauté shrimp 2 min, until pink but not completely cooked through; remove from pan.
Add 2 T vegetable oil to pan and sauté shallots 1 min. Add garlic and serrano chili and cook 1 min more. Push everything to one side of pan and add eggs in center, stirring to scramble quickly, then push eggs to side of pan. Add fish sauce mixture and shrimp, then bring to a simmer and stir together. Add peanuts, cabbage and noodles, then stir to combine. Remove from heat quickly to avoid overcooking noodles. Divide among 4 serving bowls. Garnish with more peanuts, lots of fresh Thai basil, more chilies, as desired, lime wedges and fresh bean sprouts. Serve immediately.