There should be an option to report other players, not only for insults like in moderated chat, but also when they want to leave the game and offer to exchange all their raw materials for just one to harm the rest and quit. This should lower their karma or prevent them from playing anymore, since fire isn’t fair like that.
Not just that. In casual there are a lot of players playing together and collaborating to eliminate others. They always put robber on you, try to block your path, always use cards against you. And you can’t leave? You need to accept dishonest so you don’t be punished? Ridiculous! Actually, punishment should be reviewed on those cases. Will need a lot of moderators? No, just put some kpis to evaluate this. If others players are being too much friendly between themselves and always trapping the other(s). It’s ridiculous being punished IN DOUBLE!