[@Dynamo Frokane]

Well, the republic would properly flood the market with mass-produced weaponry from their manofactoria´s, but food...well, with so many slaves working, they really could need a reliable source of food! 

For other relations, i could see the republic being quite arrogant towards your nation, yet not hostile. Treating them as "primitive Sea-dogs" they would be quite patronizing, but pay good coin for all food that they could bring, as long as they keep their pirates away from their black ships!