Someone tends to hoard all the room keys
There's typically several people trying to cyber or hitting on every single female they come across
Power goes out. A lot.
Could these possible be dealt with by complaints being sent in via chat and some sort of punishment for the offending character? (I mean, if they're the Killer, they probably could justify some of those, but usually its not the Killer doing it)
Never taser someone else twice in a row(This causes some major bug if I remember right)
Tasing someone twice destroys their entire inventory, so it can destroy the Death Note, Shinigami Eyes (I think), and potentially screw up the entire round
There's not a whole lot to do sometimes. Rounds go on for a loooooong time.
Combat is difficult, and people have a lot of health.
The rounds go on, but they are guaranteed to always end (There's a time limit), and usually if there's only two players left, someone (usually a dead character) says "Will you two kill each other already!" (Or words to that effect). It's horrible metagaming, but sometimes the two characters are quite happy to stay as they are until the round times out.
Also, in Combat, I think there's a server setting called "Weapon Lethality", if that's set high enough, it can make combat finish pretty quickly.