Some suggestive dialogue.

Homestar appears naked several times, with pixelated nudity.

Very Rarely use of fire arms

The Cheat often gets kicked as a running gag.

Blood and slapstick violence throughout. Sometimes features comically graphic violence.

Pervasive use of "crap" and each of its derivatives.

There are also plenty of references to swearing as well.

The Cheat smokes a cigarette in email #117

in epsoide date nite homestar and strong bad are seen holding a beer with a label of "cold one"

Always used comedically.

It is comparable to The Simpsons content wise.