Commerce Paypal WS already redirects automatically by using the "offsite_autoredirect" flag in hook_commerce_payment_method_info:
$payment_methods['paypal_wps'] = array(
'base' => 'commerce_paypal_wps',
'title' => t('PayPal WPS'),
'short_title' => t('PayPal'),
'display_title' => $display_title,
'description' => t('PayPal Website Payments Standard'),
'terminal' => FALSE,
'offsite' => TRUE,
'offsite_autoredirect' => TRUE,
);
The behaviour of this flag is to redirect automatically:
if (!empty($payment_method['offsite_autoredirect'])) {
$form['#attached']['js'][] = drupal_get_path('module', 'commerce_payment') . '/commerce_payment.js';
And the js is the simplest it can be:
Drupal.behaviors.commercePayment = {
attach: function (context, settings) {
$('div.payment-redirect-form form', context).submit();
}
}
So if you're experiencing a 10s delay on this operation, you need to debug what's happening in your payment page to cause this slowness. Check things like other panes you've put there (there should be just the payment one), cache, js compression and so on.