How can I tell when I have Assigned all of my Images in my Ingest folder into my Universal Catalog?
This can be using a category formula. Of the more complex sort, I'm afraid.
See the IMatch help on category formulas and then make some experiments to figure out what can be achieved.
Why is my Fully Classified, Not in the Universal Catalog, Unassigned Files, and Uncategorized Files empty?
I don't now anything about your categories or how you have set them up.
The Unassigned and Uncategorized standard categories show only uncategorized files or files not assigned to any category.
If all your images are assigned to at least one category, or referenced by a category, these categories will be empty. And that's correct.