Pierce squash with a fork; place on paper towels in microwave. Microwave at high 15 minutes or until tender. Let stand 10 minutes. Cut squash in half lengthwise; discard seeds. Scrape inside of squash with a fork to remove spaghetti-like strands.
Combine cooked squash and next 6 ingredients (through olives) in a large bowl; toss well. Combine vinegar and remaining ingredients, stirring with a whisk. Add to squash mixture, tossing to coat. Cover and chill.