Could you please add an option in config that allows you to blacklist an item to be used as currency? Also not to be allowed to be used as trade?

This sounds like this to me: #417

However, you will have to clarify what exactly you mean (is there a difference between 'blacklist an item to be used as currency' and 'not to be allowed to be used as trade'), and why this is needed / what problem this is supposed to solve.
Consider posting your description of this in the linked ticket.