Their lyrics are filled with brutality, sexuality, obscenity, and especially in their earlier works, slurs. The songs describe taboo topics, turn everything Up to Eleven and exceed all kinds of tolerable limits. "Panty Shot", "Faggot" and "I Hate Jimmy Page" are the most popular examples for this. However, they know exactly what they're doing, and none of it is supposed to be taken seriously, since it's so highly exaggerated.
Vulgarity was the name of the game for their earlier shows. Jimmy was known for waving his privates about and once tried to set them on fire. There is footage of him bringing a crowd member on stage before making out with and then teabagging him. Stuffed animals would get thrown on stage, and Steve and Jimmy would pretend to fuck them. One specific case: Jimmy drank his own urine before passing it to Steve, who took one sip and spat a second into the crowd. Jimmy then began making out with audience members.
Growing the Beard: In terms of commercial success, definitely. In terms of critical success, that's a topic of debate right there.