From your list the obvious one is adding a personality point system like Sims 2 that truly helps define the core of the Sim behavior. Now the personality traits we have need a complete overhaul before more useless traits are added so they can enhance the personality point system
they need to up their tiny budget and create new animations to make these traits feel and look different from each other. Also a memory system is needed so things that happen actually matter or having these personalities will be as shallow as it is now. Wants and fears should also return and go along with the traits that were picked and the choices we made for the Sim while playing it.
