You can't teach all players how to roleplay. Only way is to implement rules, make them read it and punish those that go against it.
In my opinion, we lack rules that could be clear for everyone, including admins to show how situations should end and doing this and that is wrong. It is true that rules list is long, but I'm pretty sure that adding more rules and clear ones could make it easier and would take less time waste in future.
Actually the problem is some players who try to find their way
around the rules, where they do the rule break right on the borderline, thus it cannot be termed as one. That mentality has to change, but there was only one Lord Buddha in this world. :P