You must enter a web address to mirror a website.
A txt file is not an entry point to a website so you must
enter the address that allowed you to display the FAQ
<http://db.gamefaqs.com/computer/doswin/file/final_fantasy_xi_mining.txt>
In your case <http://db.gamefaqs.com/> may not help.

To delete a mirror with Project name "mirror1", look for the
Base path then delete the subfolder "mirror1".