I honestly think there should just be a stronger tie between emotions and traits. As of now, the only tie between them are the occasional trait-based moodlets that sims with certain traits sometimes get (i.e. feeling flirty, etc.), other than that, traits don't really influence emotions that much and hence all sims get pretty much the same moodlets to everything regardless of traits as a result. There should be more trait-specific moodlets (like, for example have the hot-headed sims receive an exclusive angry buff in reaction to things being broken in the house) so that each sim would have a unique reaction to the same thing depending on their traits. It's already set in stone that emotions pretty much govern this game, so there's no way to work around that other than to make the best use of it - i.e. Use it as a platform for sims to display their traits.
BTW, this thread should totally go into the ideas section. It's probably more likely to catch the attention of gurus there.
