First and the most important to me, I once found a source which I can't get to right now but it stated that seeing they don't stand a chance, merchants would often surrender without a fight, after just a simple warning from the pirates. If so, what did such warning look like? How close could a ship get for a message to be understantable but not risking the ship getting away?

Okay, also: I do know which parts are the most beneficial to attack when wanting to destroy a ship but is there an actual way to just slow it down without making it useless? It seems probable that pirates wouldn't like to kill everyone on sight as it'd make them wanted more and that's not your popular wish I guess, so I can imagine a pirate taking just the booty itself, letting the crew go with their ship empty.

Also, how expected was a pirate captain to kill, either all the crew or or just the enemy's captain?

These three budge me the most but if there's anything you think I should know writing about a story including pirate attack, I'll very much appreciate that.