Can I create a star rating system with this plugin?

The Rich Snippets Plugin allows you to create Rich Snippets that produce stars in search results. However it does not allow your users to rate your blog post as it’s not a rating plugin. That means it has no built-in rating system that counts automatically.

However you can probably integrate third party rating system if they store the total rating in the postmeta database table of WordPress. Check out the documentation page for updated information about this.