drupal tablesort_sql sort by default but don't show in header

Answer 1

A quick solution would be to do something like this:

$header = array(
    array('field' => 'created', 'sort' => 'desc'),
    array('data' => t('title'), 'field' => 'title'),
);

$header_sort = $header;
$header_sort[] = array(...); // Add the default sort.

Then you can use header_sort for the sql and $header for the theming of the table.