So I've seen this quite a bit, so here is a rant:
New Role Groups:
I've seen many people come up with different role groups. These are groups that are separate from other groups. 1 group is town, another is mafia, etc. People have been creating these, however, here are some things that I should say:
1. Remember that there are only 15 people per game. Adding a new role group is difficult because then it makes it so that other role groups are "diluted" by this new idea and become less powerful. Adding new role groups are difficult because it becomes difficult to balance.
2. The game of Town of Salem is based off of SC2 mafia. The purpose of this game is to introduce that mafia type experience to players that do not own that game. This is why Town of Salem is free and will always remain free. However, this means that they will likely not stray far from the actual game. They have only removed a few powerful roles, added some helpful roles, and created many changes. Adding a whole new role group is straying away from SC2 mafia.