Set node action for specific content type
The Rules module will be able to handle this, it's a next-generation version of the actions/triggers that are included with core:


  The rules module allows site administrators to define conditionally executed actions based on occurring events (known as reactive or ECA rules). It's a replacement with more features for the trigger module in core and the successor of the Drupal 5 workflow-ng module.


You can use the "After saving a new comment" event for the comments part, and the "After saving new content" event for the content part.

In both cases you'll be able to use conditions on your rules to make sure the actions are only fired for your required content types.