you need to remove lines 17 and 18:
$WAFV_Errors .= WAValidateLE(((isset($_POST["Security_code"]))?strtolower($_POST["Security_code"]):"") . "",((isset($_SESSION["captcha_1"]))?strtolower($_SESSION["captcha_1"]):"") . "",true,4);
$WAFV_Errors .= WAValidateLE(((isset($_POST["Security_question"]))?strtolower($_POST["Security_question"]):"") . "",((isset($_SESSION["random_answer"]))?strtolower($_SESSION["random_answer"]):"") . "",true,5);
these vaidate the security form elements you removed.