Bring 2 teaspoons salt and water to boil in a large pot. Cook noodles 2 minutes less than package directs. Reserve 1 Cup cooking liquid. Drain.
Meanwhile wash and trim leeks. Cut in half lengthwise and then crosswise into 1/4" strips. Rinse slices under water until water is clear. Drain well. Heat 1 teaspoon oil in a 12" skillet on medium hi heat. Sprinkle shrimp with 1/4 teaspoon salt and black pepper to taste. Add half of shrimp to pan and cook 1-2 minutes until just pink and curled. Remove from pan. Heat 1 teaspoon oil and repeat with remaining shrimp.
In same skillet heat 1 tablespoon oil over medium low heat. Add leeks, garlic, and crushed red pepper flakes. Stir well. Cover and cook 10 minutes or until tender, stirring occasionally. Uncover and add wine or broth. Heat to boiling. Reduce heat to medium and simmer 4-5 minutes or until wine or broth is reduced by half.
Add pasta to pan with leeks. Add butter and shrimp. Cook on medium heat until noodles are al dente and glazed with sauce. Toss. Add basil, parsley, and 1/4 t salt. Cook 2 minutes longer tossing and adding reserved cooking liquid if necessary. With a zester grate lemon peel over .
Note. I kept the reserved cooking liquid and used that when reheating leftovers in microwave. Reheats well.