You're in the right place to ask for help, James Garol.
The "To Do List" feature is designed to remind users the different task that needs to be complete to ensure data and reports are accurate in QuickBooks.
If taxes were paid and settled outside QuickBooks, you'll still need to complete the tasks in QuickBooks just for record keeping purposes.
For custom tasks, the task owner just needs to follow whatever steps you put in the note. When they finish the task, select the vertical ellipses (three dots) and then Mark as complete. This should not send any type of notification to your customer.
Here I included an article that contains great information about managing tasks: Add and review tasks for your team in the Task menu.
The Community is always open if you have any other questions managing the task menu or anything about QuickBooks. I’ll be here.