Павел Рябинин

<form class="clear-cart" action="<?php echo esc_url( wc_get_cart_url() ); ?>" method="post"><button type="submit" onclick='javascript:if(!confirm("Удалить все товары из корзины?")) {return false;}' class="button" name="clear-cart">Очистить корзину</button></form>

add_action('init', 'woocommerce_clear_cart_url');
function woocommerce_clear_cart_url() {
    global $woocommerce;
    if( isset($_REQUEST['clear-cart']) ) {
        $woocommerce->cart->empty_cart();
    }
}

add_filter( 'woocommerce_get_order_item_totals', 'remove_subtotal_from_orders_total_lines', 100, 1 );
function remove_subtotal_from_orders_total_lines( $totals ) {
    unset($totals['cart_subtotal']  );
    return $totals;
}

function removing_customer_details_in_emails( $order, $sent_to_admin, $plain_text, $email ){
    $wmail = WC()->mailer();
    remove_action( 'woocommerce_email_customer_details', array( $wmail, 'email_addresses' ), 20, 3 );
}
add_action( 'woocommerce_email_customer_details', 'removing_customer_details_in_emails', 5, 4 );

Woocommerce hide subtotal
Woocommerce remove billing address from email
Woocommerce remove billing address