I was reading the infamous reply and I became curious about some of the insults they used. The reply reads:
O sultan, Turkish devil and damned devil's kith and kin, secretary to Lucifer himself. What the devil kind of knight are you, that can't slay a hedgehog with your naked arse? The devil excretes, and your army eats. You will not, you son of a bitch, make subjects of Christian sons; we've no fear of your army, by land and by sea we will battle with thee, fuck your mother.
You Babylonian scullion, Macedonian wheelwright, brewer of Jerusalem, goat-fucker of Alexandria, swineherd of Greater and Lesser Egypt, pig of Armenia, Podolian thief, catamite of Tartary, hangman of Kamyanets, and fool of all the world and underworld, an idiot before God, grandson of the Serpent, and the crick in our dick. Pig's snout, mare's arse, slaughterhouse cur, unchristened brow, screw your own mother!
So the Zaporozhians declare, you lowlife. You won't even be herding pigs for the Christians. Now we'll conclude, for we don't know the date and don't own a calendar; the moon's in the sky, the year with the Lord, the day's the same over here as it is over there; for this kiss our arse!
Were the highlighted statements things that would have been considered insults of the time? Was there a stereotype that Macedonians were bad wheelwrights? That Podolians were prone to thievery? Etc.
The geographical references in the Cossacks reply were the titles the Sultan claimed in his initial demand that they submit to his authority. The Sultan titled himself as the authority over all those locations; the professions mentioned by the Cossacks are insulting because they are base labor jobs. A modern equivalent would be Obama addressing a foreign power and signing himself as "The President of the United States and Commander-in-Chief" and them calling him "The Janitor of the United States and Toilet-Cleaner-in-Chief" in their reply.
It's worth pointing out that the Wikipedia translation of kozolupъ as 'goatfucker' is, perhaps, not necessarily appropriate. The rest of the epithets (until you get to armjans'ka svin'ja 'Armenian pig') are low-status professions, and kozolupъ literally means 'goatskinner'. I'm not sure when the obscene sense of the word arose, but it seems possible that here we don't have something that's quite so obscene as the translation makes it out.