BGMusgrave

In the original Mistborn trilogy, Kelsier wars Vin not to burn unknown metals because bad metals can make you sick and bad alloys can make you sick. This means that Mistborn can burn all metals even ones that don't grant any power. Does that mean that there are mistings that can burn metals like lead? Also, does this mean that there are way more feruchemy abilities or is it just storing nothing at which point would you be able to push/pull on the metal if it was full?