Short answers, pulled from the story.
Gaius Suetonius Tranquillus wrote the twelve biographies in 121 AD while serving as secretary to Emperor Hadrian. He dedicated the work to his friend Gaius Septicius Clarus who held the title of praetorian prefect at that time.
Modern historians criticize the book for being racy and overly reliant on hearsay rather than official documents. Suetonius included subjective opinions within what appeared to be objective historical knowledge and omitted important events without explanation.
Julius Caesar insisted the ransom price of 50 talents was too low and ordered the pirates to raise it during his captivity. After release he raised an army alone, captured the pirates, and crucified them for their actions.
Vespasian ruled from 69 AD until his death in 79 AD after founding the Flavian dynasty and rebuilding infrastructure damaged during civil wars. His son Titus finished the Flavian Amphitheater known today as the Colosseum during this reign.
John Lydus quoted the dedication to Septicius Clarus in his sixth-century book De magistratibus populi Romani allowing dating between 119 and 121 AD. The oldest surviving copy dates to Tours in the late eighth or early ninth century AD.