You can add refresh meta tag through the Admin Interface. I have attached a screenshot of this option.
On your second question, yes, the external pages are also handled. Let's say you add the external page "External_Page.aspx" and direct it to http://www.sitefinity.com. Then in your site when a request is made to ~/External_Page.aspx, in the Telerik.Cms.Web.CmsHttpModule on BeginRequest, you get redirected to sitefinity.com.
Hope this helps.
All the best,
the Telerik team
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