Wordpress: SQL Query to WP_Query Educational Fail (post__in can bite me.)

functions snippet

//These are in the Functions.php file 
//gist-1364599

function objectToArray($result) 
{ 
    $array = array(); 
    foreach ($result as $key=>$value) { 
        if (is_object($value)) { 
            $array[$key]=objectToArray($value); 
        } 
        elseif (is_array($value))  { 
            $array[$key]=objectToArray($value); 
        } 
        else  { 
            $array[$key]=$value; 
        } 
    } 
    return $array; 
}  

// turn an array-of-arrays with a bottom key of 'ID' to a list
function flattenObjectByID($object) 
{ 
    $idlist = array(); 
    foreach ($object as $val) {
        $myid = $val['ID'];  // does this work?
        array_push($idlist, $myid);
    } 
    
    return $idlist; 
}  

function flattenObjectByKey($object, $bk) 
{ 
    $idlist = array(); 
    foreach ($object as $val) {
        $myid = $val[$bk];  // does this work?
        array_push($idlist, $myid);
    }
    return $idlist; 
} 

showcase snippet

///In showcase.php (or wherever.php)

     //get the sticky_posts
     $sticky = get_option( 'sticky_posts' );
     //get id's only of child pages
     $local_children = $wpdb->get_results( "SELECT ID FROM wp_posts WHERE post_parent = $post->ID AND post_type='page'" );
                    
     //compare the results
     print_r($sticky);
     print_r($local_children);
                    
     $array = objectToArray($local_children);
     $flattenedbyID = flattenObjectByID($array);
     $flattenedbyPassedKey = flattenObjectByKey($array, 'ID');

     print_r($sticky);
     print_r($flattenedbyID);
     print_r($flattened2);

    if ( ! empty( $flattenedbyPassedKey ) ) :

					
    $featured_args = array(
        //post__in THIS DOES NOT WORK B/C post__in only works with POSTS!!!
	'post__in' => $flattenedbyPassedKey,						
	'post_status' => 'publish',
	'posts_per_page' => 10,
	'no_found_rows' => true,
    );

    // The Featured Posts query.
        $featured = new WP_Query( $featured_args );
     print_r($flattened);