Place first 9 ingredients in a food processor; process until smooth, scraping sides of processor bowl occasionally.
Combine scallops, flour, and 1/8 teaspoon salt in large zip-top plastic bag; seal, and shake to coat.
Heat margarine in nonstick skillet over medium-high heat. Add scallops; cook 3 1/2 minutes on each side or until scallops are done.
Combine pesto mixture and pasta in a large bowl, tossing well. Arrange 1 cup pasta on each plate, and divide scallops evenly between plates. Sprinkle with pepper; garnish with parsley, if desired.