Coat a large nonstick skillet with cooking spray; add oil. Place over medium-high heat until hot. Add squash, mushrooms, crushed red pepper, and garlic; saute 3 minutes. Add tomato and salt; saute 5 additional minutes. Set aside, and keep warm.
Wash beans; trim ends, and remove strings. Cut beans into 1-inch pieces. Bring water to a boil in a Dutch oven; add beans, pasta, and carrot. Cook 8 to 10 minutes or until pasta is tender. Drain well; set aside, and keep warm.
Melt margarine in a small saucepan over low heat; add flour, stirring until smooth. Cook, stirring constantly, 1 minute. Gradually add milk and broth to mixture, stirring constantly. Cook over medium heat, stirring constantly, until thickened and bubbly.
Combine pasta mixture and vegetable mixture in a large bowl. Add sauce; toss well. Sprinkle with cheese. Serve warm.