Some pretty interesting poins, OP.
Pirates in 3rd rates gave me headaches (pun intended) from day one.
Piracy should be all about hit&run in small, fast vessels, stuffed with guns and boarding parties.
Naval Action should not miss the chance to make piracy demanding and more historically accurate.
So: plunder, plunder, even more plunder. Not nation building and building pirate Navies as large as only the most sophisticated and rich European countries could afford to maintain.