What if you don’t want to use bacon fat, can you use something else and how much?

Hi Kathleen! The flavor will be different, but you could swap in about 1/3 cup of butter or shortening.

Sure you can, but you'll change the whole profile of the biscuit. If you don't mind that, wipe the pan out after removing the bacon and proceed, using a neutral vegetable oil, such as grapeseed or peanut oil.