Stainless steel cookware scratches
Of course stainless utensils can be used on stainless pots and pans; otherwise, the restaurant industry would come to halt.

The only time you need to use utensils of specific materials is pans with a non-stick coating that can be scratched, such as using plastic for PTFE.

As to your alleged "metallic leaching," that is not typical at all to stainless steel cookware.  You would have to provide more information to get a good answer.