How to trade

Hey all, I am currently in the year 1402 in my Austria playthrough and i am playing tall and trying to expand mostly just through PU's (already have Bohemia as a PU, trying to prevent them from taking over seniority is kinda tough) so I really need to boost my economy. I have barely expanded any silver mines at all, so there is a lot of potential money to be made there, but the demand for silver is just so low that it is hardly worth it.

I tried using the "Create Export Trade Order" but that never gets used because "no profitable trades could be found", but markets out of my reach do have higher than average silver prices.

I am pretty sure Venice has quite a decent trade range, so what if I were to flood the venice market with silver? Would the ai nations eventually start importing from venice, over time creating a profitable trade for me? Or would I just be wasting trade capacity with that and should rather just leave the automated trades try and trade for profit?