The player behind the character will eventually show through. Where roleplaying really is important is a) making decisions (do you make decisions that reflect the character you\'re playing?) b) dialog (it would be a boring game if your character did all the talking automatically c) where and how the character spends time.
I think knowledge of certain things (secret codes etc) should not be something spreadable by IM, email, forum, etc. One way to get around this is invisible \"items\" in the inventory - you can\'t actually speak the password unless you\'ve overheard it. Still, to prevent the game from being too dry the game could tell you what the password *is*, it just wouldn\'t help out anyone you gave it to.