Just some observations:

Lenny Bruce got famous by being insulting.
Red Skelton and Bob Hope never insulted anyone.
Humor is in the mind of the reciever.
Bigots can't laugh.
White people should never say "nigger".
Black people should never say "honky".
Christians should never say "kike".
English should never say "micks"
etc.

Truth can be humorous.
Truth is humorous because it is true.
Truth can be painful.
Truth can be healing.
Truth is sort of like a gun--never point it at something you don't intend to kill..........