I tend to click the 'rate up' button when I go into my hubs to respond to comments. Does rating my own hub up affect my hub score negatively, or is my rating up counted the same as anyone else who might rate my hub up?
Comments from other hub users has a positive effect on your hub ratings. As does traffic generated from google. If your hub is being indexed highly by google than it meets the criteria for high SEO. Search engines love original content and lots of it. They also factor in how many backlinks are pointing to your hub and his will also help raise the SEO score as well as your particular hub score.
You can help the HubPages community highlight top quality content by ranking this answer up or down.