Hide php Notices in Dashboard

I don’t know how to move the notices to the bottom or if that’s possible at all. To disable the debug mode in wp-admin write in wp-config.php:

define( 'WP_DEBUG', FALSE === strpos( $_SERVER['REQUEST_URI'], '/wp-admin/' ) );

Untested:

You could try to enable warnings in admin with:

// happens early in wp-admin/admin.php
add_filter( 'secure_auth_redirect', 'wpse_67728_error_warnings' );

function wpse_67728_error_warnings( $in )
{
    // anything but notices
    error_reporting(E_ALL ^ E_NOTICE);
    return $in;
}