ShrineDesigns, after swapping email with one of the developers over at WordPress.org support, I learned that the WP get_currentuserinfo() may not be able to query on custom fields in the WP DB, but that wp_get_current_user could.

With that in mind and using some of your code examples, I've come up with a hybrid version that's still not exactly correct syntax and wanted to run it by you. This is what I have that's throwing an - unexpected T_ARRAY error on my line that begins with - $custom_field =. Using the WP codex support suggestion, this is what my code looks like now:

PHP Code:
// Call WordPress function get_currentuserinfo()
// For 4 standard WP fields and wp_get_current_user()
// To call 4 custom WP user fields
    /**
     * @example Safe usage: $current_user = wp_get_current_user();
     * if ( !($current_user instanceof WP_User) )
     *     return;
     */

function get_currentuserinfo() {
global 
$user_firstname$user_lastname$user_email$user_login;
      
get_currentuserinfo();

function 
wp_get_current_user() {
$custom_field = ($data) array('mepr-field' => $user ));
$data $custom_field->{'mepr-field'};
if ( 
$current_user->array_key_exists'mepr-field' ) ) 
     
$current_user->get'mepr-field' ) ;
     
global 
$mepr-address-one$mepr-address-city$mepr-address-state$mepr-address-zip;
      
wp_get_current_user();

    
$data = array(
        
'firstname' => $data['user_firstname'],
        
'lastname' => $data['user_lastname'],
        
'email' => $data['user_email'],
        
'username' => $data['user_login'],
     );

    
// address
    
if (array_key_exists('mepr-address-one'$user))
        
$data['address'] = $user['mepr-address-one'];
    elseif (
array_key_exists('mepraddressone'$user))
        
$data['address'] = $user['mepraddressone'];
    
// city
    
if (array_key_exists('mepr-address-city'$user))
        
$data['city'] = $user['mepr-address-city'];
    elseif (
array_key_exists('mepraddresscity'$user))
        
$data['city'] = $user['mepraddresscity'];
    
// state
    
if (array_key_exists('mepr-address-state'$user))
        
$data['state'] = $user['mepr-address-state'];
    elseif (
array_key_exists('mepraddressstate'$user))
        
$data['state'] = $user['mepraddressstate'];
    
// zip
    
if (array_key_exists('mepr-address-zip'$user))
        
$data['zip'] = $user['mepr-address-zip'];
    elseif (
array_key_exists('mepraddresszip'$user))
        
$data['zip'] = $user['mepraddresszip'];

    return 
$data;
    }

I removed two fields from the WP user array and added them to the $query_vals array when I discovered I can't get the WP user password out of the DB in plain text because it's encrypted, so I'm going to pass a static value of the same password for all users to the receiving site and because the country will always be the US, I moved that field up also.

How is my syntax incorrect?