The show makes light of Dan's obsessive quest for revenge against those responsible for small offenses like scratching his car, and some of the stories have violent ends that result in the implied deaths of those responsible, as well as innocent bystanders. Violence and destruction are seen as a reasonable means to an end for minor offenses. Potty humor includes references to peeing.
Fistfights, car accidents, mock strangulation, and weaponry (guns, swords, etc.) are common, and sometimes people are shown injured. It's often implied that people are killed as a result of Dan's rampages, but there's no blood or gore.
Female characters are shown in tight, revealing clothing and playing up their sex appeal for attention or to get something they want.
No cursing, but there's a constant stream of other marginal language from Dan, including "jerk," "stupid," "heck," and "shut up." He's also prone to calling people names and making verbal threats.