Are templates available for the default notifications which can then be edited?
No. The default notifications are not available as templates to be added. However, all fields normally available in a default notification are can be added to a template created from scratch.
Where do I define how the template will be used?
At the bottom of the General tab of the notification template you will find a “Defined For” drop-down list to choose for which object the template should be defined. The fields available in the Object Navigator will vary by the object that has been chosen.
What makes the Approve button appear on the invoice approval notification email?
The approval button in the invoice approval email appears as a result from the rule configuration and is not controlled by the configuration of the email template. This is new functionality in TeamConnect 4.0.
When emails are configured on rules, will emails only be sent if the action completes successfully?
Using the Post-Commit rule type for notifications will ensure that the Notification is not sent until the action commits to the database.