Do you generate the site-map XML file or is there an easier way to manage and place my own XML file?

PRESSERO > *Pressero FAQs
In general the sitemap.xml is automatically generated. But you can manually override it in the Site Settings --> SEO/HTML --> Edit Sitemap.xml Contents area. If you want to override the automatic sitemap.xml, the contents you put in this area must be a valid site map xml format (http://www.sitemaps.org/protocol.html).  

After you clear out the "http://www.sitemaps.org/protocol.html", be sure to click save. Then you will want to clear site cache. You can read about how to do that here:  http://support.aleyant.com/kb/a399/custom-skin-changes-are-taking-too-long-to-show-up-on-my-site.aspx