I'd guess everyone tries to play his race according to the settings, but since they are so few guidelines, people will always clash about trivial things like purr/not purr while others simply won't care. Besides, not everything can be preset (physiology, psychology, sociology, customs... the Book of Infinite Pages).
To help, I'd like a little info window reminding me IG what my race is all about, something like the little text at character creation.
Actors will also have to add adverbs to their emotes sometimes, so that others have a chance to catch if an action is supposed to be common, rude, slightly mad... How do I know if this smiling Enki is happy to see me or actually showing his teeth to warn me to keep my distances? A little added word to show the intent of an action cannot harm.
If one day we have race-related emotes, that would solve some of the issues here: for enkis, /purr and /roar for example.
One more thing about RL influence on the settings: when basing choices on RL small cats / big cats for instance, one tends to forget the 3rd choice, that is non-RL feline bipeds that can be completely different; they wouldn't bark, since we, real world players, would get confused, but they can have their own sounds, even making use of new verbs. Yes, that's right, Enki don't purr, they schrar and frit. ... or maybe they purr as well?