what does 'tokenactions' do (versus tokens) - and what if not enabled?

The "enhanced actions" are added to the core Drupal actions (nothing to do with pathauto). If you enable it, then in admin, go to Site configuration->Actions, under Make a new advanced action available you'll see three new actions at the bottom: Display a tokenized message to the user, Send tokenized e-mail, and Redirect to a tokenized URL.

I was also just wondering about this. This is an incredibly useful module, but I think few people even know it exists. A bit more documentation would be very helpful (maybe on the Token documentation page).

I have updated a documentation/tutorial at http://drupal.org/node/298506