If the trigger test returns an error this can be due to an error in the data source.
Mail from the action test does not contain any data!
The data only gets appended when the action is executed by an actual trigger, not by the test.
How can I share my automations?
Assuming you have the necessary permissions you can share an automation in the overview menu, just like other elements, by clicking the on the right side of the regarding the element.
Right now it is not possible to share automations via group management like other elements.
Do I need to share the used datasets/scripts for an automation to work?
No, everything should still work for a user without access to the used data sources. They should also be able to change actions or filters applied to this data source as well as creating a copy of the automation. The only restriction is that if this user selects a different data source he will not be able to reselect the old data source without the necessary permissions.
Is it possible to create a template automation?
Yes, just create a normal automation and share (with read permissions) with the users which are supposed to use the template. These users will be able to create a copy of the template, which he then is able to alter.