We would like to create a self service workflow so that staff can use the system to translate documents themselves. Specifically the "translation" step will be done by the person requesting the project.

Suggestion...

When defining a workflow have the ability to assign tasks to a special user "Created By". When a project is created from the template / workflow this would be replaced by the user who created it.

Notes...

A similar result could be achieved manually assigning the tasks to a dummy group and then reassigning them manually when you create the project. However this is extra steps and is prone to human error.

One error situation to consider - If the project is created by someone who doesn't have permissions for the assigned activity. I think this would only occur if requested by a customer requestor so maybe these project templates should not be available to them.

If available we might choose to use this for the error step. If would often make sense if that was directed at the requester to sort out.