Following the tutorial I had 3 objects in the cell, and I tried deleteing 3 of them after issues getting them to snap, they wouldn't delete, 2 of them became pink.

Then I loaded a different cell, then reloaded the LokirsTomb and 2 of the objects were gone. The 3rd object cannot be clicked on or edited in the render window. Then reloading the cell again, the 3rd object is missing from the object window but it is still inside the render window.

What are you doing exactly? How do you 'delete' the object?