Add warnings before deleting tasks that are in workflows, or deletion protection.
If a task is in a workflow, and I delete it, it just vanishes from the workflow. This can break the workflow.
At minimum, when deleting a task, it should display a warning if it is being used in a workflow.
Even better would be if it was able to flag a task as undeletable, at any point, or if it is used in a workflow. This could be set system wide, or in a specific workflow.