These are in no way the definitive be all and end all rules for a convention, they are only a guideline...a place to start, but they may give pause before you jump head first into starting your own convention.
It's not as often that you hear about celebretires walking away disgruntled with a con. They tend not to voice their dissatisfaction in the fear that it will give them bad press and ruin further invitation to events. They also don't want the negative publicity that could ruin their careers..Villains con, left many with a bad taste.