unwanted user_meta data when creating new user?

Trying to create new user if not exists from e-commerce plugin checkout page.

Prior to submitting cart form data to PayPal, an ajax call is made passing cart form data to checkout.php which updates the db_cart, but also checks for existing user, the idea being — to verify existing user, or create new — and log in before submitting the order to PayPal. But for some reason which I cannot begin to fathom, when creating new users, wp adds ALL cart data to the new user_meta no matter what approach I take to creating the user.
Here is the ajax Post cart data

Array
(   [cmd] => _cart
    [upload] => 1
    [currency_code] => USD
    [business] => [email protected]
    [address_override] => 1
    [cpp_header_image] => URL
    [cpp__headerback_color] => 4733AB
    [cpp_payflow_color] => 4733AB
    [cancel_return] => URL
    [return] => URL/my-orders?thank_you&cart_id=ADMINbLujO_CART4ea1b8f80a939
    [cbt] => Return to Demo Z
    [item_name] => ADMINbLujO_CART4ea1b8f80a939
    [amount] => 48.87
    [handling_cart] => 4.97
    [email] => [email protected]
    [user_pass] => testpass
    [first_name] => Suzie
    [last_name] => Queue
    [address1] => 2415 Lamar St
    [address2] =>
    [city] => Edgewater
    [state] => CO
    [zip] => 80214
    [country] => US
    [item_number_1] => ADMINbLujO_4e8f31f565a70
    [item_name_1] => Wonder Widget
    [quantity_1] => 1
    [amount_1] => 43.90
    [buyer_first] => Joe
    [buyer_last] => Blow
    [user_cnfm] =>
    [ship_to_self] =>
)

and here is the code from **checkout.php**

<pre>
foreach ($_POST as $key => $val) $$key = $val;
if(!is_user_logged_in())
{	if($userID = email_exists($email))
	{	$user_info = $user_info = get_userdata($userID);
		$user_login = $user_info->user_login;
		$display_name = $user_info->display_name;
		$welcome = "Welcome Back $display_name!";
	}
	if(@$welcome)
	{	if(!$user_cnfm) die($welcome);
		$auth = get_object_vars(wp_authenticate($user_login, $user_pass));
		if(array_key_exists('errors',$auth)) die("Password Error");
		wp_set_auth_cookie( $userID, true);
		wp_set_current_user($userID, $user_login);
	}
	else
	{	$buyer_name = "$buyer_first $buyer_last";
		$ship_to_name = "$first_name $last_name";
		$buyer_region = $buyer_city = $buyer_country = $buyer_ctry_code ="";
		if($ship_to_name != $buyer_name)
		{	if(@$_SESSION['visitor'] || set_visitor() == true)
			{	foreach($_SESSION['visitor'] as $key =>$val)
				{	$new_key = "buyer_$key";
					$$new_key = $val;
				}
			}
		}
		$userdata = array(
			'user_login' => $email,
			'user_email'=> $email,
			'user_pass'=>$user_pass,
			'first_name'=>$buyer_first,
			'last_name'=>$buyer_last,
			'display_name' =>$buyer_name,
			'region' => $buyer_region,
			'city' => $buyer_city,
			'country' => $buyer_country,
			'ctry_code' => $buyer_ctry_code
		);
		$foo = print_r($userdata,1);
		$userID = insert_user($userdata);
//		$userID = insert_user($userdata);
//		$userID = wp_create_user( $email, $user_pass, $email );
//		$userID = regNewUser($userdata);
		die("New User ID $userID");
		wp_set_auth_cookie( $userID, true);
		wp_set_current_user($userID, $email);
	}
}
if(is_user_logged_in()) die("User is now Logged In");
else die("Error");
?>
</pre>