Minuteman International Fireplace Fireback, Iron, Black

The directions say this is made to rest directly on the floor. Has anyone done that instead of using 'feet' ?

Is seasoning the fireback with small low heat fires recommended for this product to prevent cracking with larger fires?

Since one review said this fireback cracked in half after two months, I am leery. Do you offer a warranty on this item?

Which feet fit this particular fireback? Got a part number?