Most likely a misspelling and combination of "shiv" and "shank", two common weapons most frequently seen in a prison context. Both are slang terms for a knife of low quality, often an improvised one. In other words, the yuppie has been stabbed.

A British heavy metal band started in the 70's and still playing today. They were accused early on in their careers of being Devil worshipers (their third album was titled "Number of the Beast"). This reference plays on that conception, probably still held by some today.

A reference to the reign of the Julio-Claudian emperors over the Roman empire, beginning with Julius Caesar in 49 BC. Julius Caesar ruled until he was murdered on the ides of March (see Regarding Steven), 44 BC. After his death, Octavian and Anthony struggled for power until 31 BC, when Octavian emerged victorious; he would later become Augustus Caesar in 27 BC and preside over the Pax Romana, or the golden age of the Roman Empire. Upon his death in 14 AD, he was succeeded by Caligula, Claudius, and finally Nero Caesar, the last in the line and often regarded as the worst of the Roman emperors. He is famous for supposedly playing his lyre while Rome burned to the ground. So technically, "Caesars and Neros" is redundant, since Nero was part of the Julio-Claudian line.

Though this phrase does appear in the "good book" (i.e. the Bible), Matthew, chapter 5, verse 38; "Ye have heard that it hath been said, An eye for an eye, and a tooth for a tooth"), this reference actually originates much earlier than this, in the code of Hammurabi, the king of Babylon in the 18th century BC. The Bible does not go so far as to say that this is a sin, so much as it advocates tolerance: "whosoever shall smite thee on thy right cheek, turn to him the other also."