How do Tasks trigger for encounters in the future? e.g. for scheduled encounters/appointments? Do they show up right away? Will I see tasks for all of my recurring future visits?

Yes and No. 

The tasks will be triggered and entries will be created within the TREAT system, however you as a user won't see them all right away. Depending on the task (and if there is a trigger threshold specified), you won't see them until around the admission date of the encounter.  So if you schedule an appointment for next Tuesday at 3pm and you have a Progress Note task due for that encounter, then the task will be generated once you schedule that appointment, but it won't be viewable on your task list until next Tuesday at 3pm.