Are there circumstances when it is appropriate to employ mercantilist ideas to promote a favorable balance of trade?
No, not according to most accepted economic perspectives (and Mercantilism is an archaic form of economics). Now, having said that, mercantilism can certainly get you a "favorable" balance of trade; where favorable is assumed to mean positive (more exports). This, in fact, is the primary mechanism of Mercantilism's heavy protectionism. A positive balance of trade would be secured by dictated tariffs or outright bans on imports. The goal was ...
A discussion on the use of mercantilist ideas for promoting a strong balance of trade.