Pierce squash with a fork. Place in a glass pieplate. Microwave at HIGH 7 minutes. Turn squash over; microwave 11 minutes or until tender. Cool. Cut squash in half; discard seeds, and remove spaghetti-like strands with a fork, discarding shells.
Whisk together vinegar and next 3 ingredients in a large bowl; add squash and remaining ingredients, tossing to coat. Chill at least 2 hours.