They're immortal so they probably have a lot of time on their hands. The last powerful deity who got upset and wanted to destroy everything was Mother Earth, herself. [ Val's come to the right place to complain then. ]

Yeah, but the gods have got some ghostly Judges handling the everyday cases. [ Unless a god or goddess comes down and goes "Hey, Hades. I'd like this person to have special treatment" the punishments are typical. ]

Never really asked. Though I guess for those who are being punished forever it'd be because the gods and goddesses know how to hold a grudge for a very long time.