On this board you appear to have quite a few choices: pirate ships, big money with +coin actions, and a nobles and bazaar engine, some mix of those together. A treasure deck with terminals such as baron and couple of merchant ships is going to be solid enough, is not going to be set back by pirates, and you can add bazaars for 5 coins as well. A pirates deck will take many turns to give a big income, may not actually bring in much more income than a baron at +4 coins or a merchant ship at +2/+2 coins, and in two player games the attack is going to be ineffective against those income cards. We should rule that out. A massive nobles and bazaar engine that can draw the whole deck is harder to evaluate. It needs +buys to make it worthwhile, needs a lot of building with expensive cards at cost 5 and 6, it can build a bit longer (since the nobles points stop an opponent building too big a lead), it will be unreliable without trashing (pirates help it), and needs a big payload (which comes with bazaar coins). I'd say the massive engine was worth going for, just because it gives you more control when it works.
Ok so lets go back to the way you played the pirates. First of all you don't need the ironworks. There are just not enough good cheap cards to make it worthwhile. Attacks are not going to stop you from buying pirates. The delay in gaining the pirates is important. So just buy the pirate ships. You should also stick purely to pirates since you're planning to make them earn more than merchant ships (or else you'd just skip the pirates, right?). You pick up an embargo and then embargo the embargoes, which is not really making use of it at all. If you're playing pirates you could embargo gold, or perhaps nobles, without any loss and even an embargo on provinces changes things for your opponent.