One of the main purposes of pirate tactics was to scare their targets into surrender. They preferred to accomplish that without doing major damage, but they were willing if it seemed necessary
Equally frightening but more devastating in its effects [than bombardment with hand thrown explosives] was the broadside. This was rarely used by pirates because they did not want to damage a potential prize,
(from chapter 6) which supports the position taken in the question, but the book continues
but they had no hesitation in firing a broadside if they needed to blast a victim into submission.
and they did, at times, employ tactics like overloading the guns. We continue
Captain John Frost was chased for twelve hours by a pirate ship in July 1717. It was nine o'clock in the evening when the pirates drew along side. The pirate ship, which was commanded by Frenchman Captain La Bouse, had twenty guns and a crew of 170. She fired a broadside of "double rounds and partridges, and a volley of small shot,"
which means that each of the ten guns on one side of the ship was loaded with two round cannon balls and a bag of partridge shot.
Note however that they made non-resistance pay:
Pirates did not appreciate a brave resistance from a merchant ship, but expected and demanded instant surrender. [...] If a merchant ship surrendered without a fight, the pirates usually refrained from inflicting violence on the crew.
A second major tactic was to carry an unusually heavy crew to allow for overwhelming boarding actions. Notice the 170 men on a twenty gun vessel in the proceeding bullet point. That was a huge crew, exceeding that used by the navies of the time.
Pirates often did not want to capture the vessel: they wanted to loot it. As long as it wasn't sinking too fast, they were happy.
One scenario documented in the book (chapter six) ends
Having striped the Princess Galley of everything of value, the pirates who were led by George Lowther, sailed away. Captain Wicksted was left to make his way to Barbados with the remains of his crew.
When they had finished looting the Samuel, the pirates turn their attention to the crew. All except one Irishman and the Captain were forced at pistol point to leave the ship and join the pirates. [...] Captain Cary was left with one seaman and three passengers. With their assistance he sailed the ship to Boston and reported the attack [...].
Wooden ships tend to sink slowly (or at least more slowly that steel ones) and could often be saved if the crew could concentrate on the problem (i.e. were not busy fighting a boarding action). A well manned ship had at least one carpenter on board plus tools and stock for him to use. I'll give one indicative quote (chapter 6):
The pirates had no difficulty in recruiting ordinary seamen to their ranks, but they also needed men with specialist skills. Of these the most in demand were carpenters and coopers. In a naval warship the carpenter was one of the most valued men on board. [...] He was responsible for the maintenance of all the wooden parts on the ship, which included most of the structure from the keel to the masts and spars. [...] [He] really came into his own during and after a battle, when he and his mate would be called upon to patch up holes in the hull, repair damaged gear, and replace broken spars.
Mangling the rigging of the opposing ship was a standard tactic of the day. Warships would have carried consider quantities of extra lumber, line and canvas and so the crews would be able to effect at least partial repairs at sea. [Citation needed, I'll have to take a little time to scan the book again to find a decent quote.] Merchant vessels may have been less well equipped.