For random order I add the following code within a custom template "tpl_basic_list":
shuffle($items);
Never tested this in a native seblod template like seb_table or seb_blog. However you could try hacking the template by adding this code straight after the line
$items=$cck->getItems();
shuffle($items);
If it works you could then create your own template based on the one you are using (copy and rename it) then add the hack there so updates do not override. here's a link on how to copy a seblod template and rename it and install