yes, if you want it to go to the login page on failure, then you need to tell it to go to the login page on failure.
your code:
<?php
if (!WA_Auth_RulePasses("Logged in to userauth")){
WA_Auth_RestrictAccess("userauth_Error.php");
}
?>
is telling it to go to the userauth_Error.php page if the page access rule fails. Change that to point to the login page.