HTTPS for home page

That’s a pain. Don’t do that. You can use a piece of code in your theme’s functions.php (or in a custom plugin). Change ‘5’ to the ID of the post you don’t want to be secure.

function custom_force_ssl( $force_ssl, $post_id = 0, $url = '' ) {
    if ( $post_id == 5 ) {
        $force_ssl = false;
    } else {
        $force_ssl = true;
    }
    return $force_ssl;
}

add_filter('force_ssl' , 'custom_force_ssl', 10, 3);