If we allow 3 users/e-mail, then some players will use 6-9-12 users, because they can never win something by playing fair. The rule for 1 user/player was the most innovatory idea and it was the reason why many old players (including me) started playing TheCrims again. Rabbits apart, I really like the idea of people not being able to refuse more than 3 challanges, but the procentage should be really low, because then players will abuse that aswell. It's a double-edged sword, but maybe we can think of something and change it.
The whorehouses were only splitting the players/hunters and it has the same purpose as the nightclubs, getting energy and hunting for skill.