1. Place first 4 ingredients in a large bowl. Combine oil, 1/2 teaspoon salt, and next 4 ingredients in a small bowl. Pour 1 tablespoon oil mixture over vegetables, tossing to coat. Marinate 15 minutes.
2. Preheat grill to medium-high heat (350° to 400°). Grill vegetables 5 minutes or until tender. Cut into bite-size pieces. Cover and keep warm.
3. Prepare pasta according to package directions. Toss hot pasta with crème fraîche and remaining oil mixture. Stir in remaining 1/2 teaspoon salt. Toss pasta with vegetables; garnish, if desired. Serve immediately.