Override and add a link to a themed table
yes copy the whole function to one of your own and add the operation. this is not dynamic.

for the other table, if you use an entity you could add the operation via the entitycontroller, only found this for d8 in the rush .. Custom entity operation links

for the d7 way http://drupalcontrib.org/api/drupal/contributions!entity!includes!entity.ui.inc/class/EntityDefaultUIController/7