It won't hurt being there, however you need to remove the cpheader(); and cpfooter(); lines as that will cause parse errors.
If you do move it into the forums directory I suggest that you add this code after require('./global.php'); so that only admins can view the page, and everyone else gets the no permission error.
PHP Code:
if ($bbuserinfo[usergroupid]!=6) {
show_nopermission();
}