Anything that would damage the tool / anvil is abuse. Any use for which the tool / anvil was not designed could be considered abuse, including using too heavy a hammer for the size of the anvil.
Go to the forge and make a hook in the style and size (10, 13, 15, 20 mm stock) of your choice. Locate 2, 3, 4 wall studs to share the load and hang the sword.
Respectfully you are missing the point. You are suppose to use the proper tongs of the correct size and shape for the work you are doing. Mr. Hofi shows the proper application of the whoop tongs in his tutorial. Bolt tongs are for bolts, blade tongs are for blades, bar tongs are for bar stock, etc. It is dangerous to use tongs on sizes and shapes they were not designed to handle.