Heat grill on medium-high. Cook noodles per package directions and drain.
Meanwhile, in small bowl, combine lime juice, 2 tablespoons olive oil, fish sauce, brown sugar, and Chile.
Rub skirt steak with remaining 1 teaspoon oil and grill to desired doneness, 2 to 3 minutes per side for medium-rare, basting with 1 tablespoon dressing during last 2 minutes of cooking. Transfer to cutting board and let rest at least 5 minutes before slicing.
Divide noodles among bowls. Using julienne peeler, julienne carrot, cucumber, and radish. Top noodles with vegetables, sliced steak, and herbs. Serve with remaining dressing and peanuts if desired.