Most of the time these are nothing to worry about (though the plugin/theme developer should know about these so that they may fix them in a future release). PHP warnings and notices are nothing to worry about on a production site most of the time.
Add this in your wp-config.php file
ini_set('display_errors','Off');
ini_set('error_reporting', E_ALL );
define('WP_DEBUG', false);
define('WP_DEBUG_DISPLAY', false);If you already have
define('WP_DEBUG', false);Replace above line with code provided.