If as list is not referenced by its settings can the list safely be deleted?
ie not referenced in anything below
Yes, it should be safe to be deleted as long as it is not the parent of any other list.
I could see that the list the used as a format.
Anaplan would not allow you to get it deleted unless you free it up. Once you are clear with all the three tables above, then you are good to get the list deleted.
Adding to what @Misbah has said I would want to share one more check that you could possibly perform :
Scenario > It might be a possibility that this list is used as a staging list in a series of actions to store a data set temporarily(maybe in properties). So I would advice you to check the 'actions' section as well to find if it is not used as a source/target in any of the actions.