Chuck is a dog-like creature that is frequently abused in various ways. Although he is immortal and can’t die and regenerates from his wounds almost immediately. His blood is also purple instead of red.
Brief is beaten up by bullies several times in his debut. Also he’s beat up by Panty and Stocking several times who aren’t really schoolyard bullies, but are definitely assholes to say the least.
Panty and Stocking are electrocuted as punishment for a murder they didn’t commit, although Stocking is more aroused by the electrocution then in genuine pain
There’s a joke about how Stocking is about to turn emo and how she needs to change before she begins cutting herself, but she never reaches this point.
Stocking’s defining character trait, although her status as an angel renders her immune to gaining weight or other health problems that would normally arise from this.
One episode is entirely dedicated to this as it revolves around a ghost turning people fat out of spite for he own weight including stocking. Panty mocks both Stocking and the ghost for this and makes various fat jokes at their expense.
In a flashback from years before the show started, Gaterbelt is murdered by rival gang members, so technically yes. It should be noted that he is resurrected by god and cursed with immortality, so his death, nor a later one of his, aren’t permanent.
A few incest jokes but no actual incest relationships although some of Scanty and Kneesocks conversations with each other can be highly questionable at points.
It's practically the entire series. Panty wants to have sex with 1000 men before returning to heaven, and most of the series is full of those kinds of jokes.
The show ends on an unresolved cliffhanger of a main characters betrayal and the death of another. Although it’s an unhappy ending on paper, it’s played up in the show as a joke to troll it’s audience. This was meant to be continued In a second season but was quietly cancelled when most of the people who worked on the show formed a new studio and the old one refused to give them the rights or continue the show.