Swearing and cussing depend on TWO things:
1. An offensive element to the word or phrase, commonest examples being
a) BLASPHEMY (insulting use of the names of sacred gods, the gods' representatives, or places), and - -
b) REFERENCE TO BODILY FUNCTIONS AND EXCRETIONS NOT SOCIALLY ACCEPTED (work out your own four-lettered Anglo-Saxon variants)
2. An element of personal violence - violent emotion such as anger or contempt being usual. Without this the use of 'swear words' are rendered innocuous. A wonderful example of this occurs in episode two of The Matrix when the Merovingian demonstrates the excellence of French for cursing, the language itself being so elegant and eloquent. Naturally it does not sound at all like swearing in English.
Many English cuss or swear words also relate to the attributes we associate with the proper use of the word. For example, a mule is stubborn, contrary, sometimes mean, will sometimes bite, does what it wants on its own time, does not respond to reasoning or negotiation (including bribes), and is somewhat an obnoxious beast to work with even though it is can bear great burdens and assist humans to move items or a person over great distances. The common cuss word that takes its name from the other word for a mule therefore takes qualities we associate with a mule and transfers those qualities onto the person who is being called the name. Obviously, name-calling and cussing is rude behavior.