Wanted to make a thread on how the existing traits should be improved in my opinion so they add more personality depth and actually affect sims so here's a list on the existing traits and how their autonomy can be changed so they actually affect the game and give townies personalities!

Emotional Traits:

Active - These sims should autonomously perform more fitness related interactions than other sims, they should appear very frequently on gym lots, go jogging regularly, will get bored in conversations quicker and will be harder to build relationship with if your sim is lazy.
Cheerful - These sims should autonomously try to cheer other sims up, should be visibly happy most the time.
Creative - These sims should autonomously perform more creativity related interactions (ie painting when there's an easel) and they should appear much more frequently on museum lots than other sims.
Genius - These sims should autonomously appear more regularly on lots like libraries, use computers more and be the main attendees of events like geek con.
Gloomy - These sims should be sad more than other sims, and should avoid busy places and social situations more.
Goofball - These sims should make mistakes more, fall over more, laugh more, and use mischief or playful interactions much more than other sims.
Hot Headed - These sims should autonomously perform rude interactions with other sims and get into fights much more often.
Romantic - These sims should be flirty often, serenade sims, and be happiest when on dates. They should autonomously spawn on lots like bars and lounges more than other sims.

Lifestyle Traits:

Adventurous - These sims should spawn more often in places like Selvadorada, Strangerville and Mt. Komorebi and participate in more activities.
Childish - These sims should automously make jokes more often, even if it's inappropriate and generally be happy.
Dance Machine - Should spawn more than other sims at nightclubs or similar lots, and dance to music when it's playing much more often.
Clumsy - These sims should make mistakes more, fall over more and laugh more.
Erratic - These sims should be visibly "crazy" (shaking, talking to themselves in public, running manically rather than walking, be scared for no reason) and other sims should get frustrated or confused when interacting with them.
Lazy - These sims should spawn in community lots much less often than others (and will NEVER spawn in gyms) and should avoid any active activities.
Snob - These sims should be rude to other sims, talk down to poorer sims and should avoid visiting lots worth less than 50k. There could be animations showing them looking at other sims furniture or clothing choices in disgust and they should be more critical and impatient at restaurants.

Social Traits:

Evil - These sims should be rude, hard to talk to, should cause chaos (break toilets, sinks, etc, start fires), will make fun of sims with low hygiene and could even be mean to children and toddlers. These sims should laugh and point at other sims misfortune (ie peeing themselves, setting themselves on fire, getting electrocuted) and this could also be linked to sentiments so evil sims will remember these embarrassing moments and mock sims for it in future.
Loner - These sims should avoid community lots and rarely be seen outside of their house. They should become tense in social situations.
Mean - These sims should autonomously perform rude interactions with other sims, be hard to talk to and get into fights much more often. They could also make fun of other sims' misfortune.
Outgoing - Outgoing sims will be out most the time and will regularly be seen at bars/community lots, will regularly autonomously introduce themselves to other sims and will spend most of their time socialising.

If anyone else has any other ideas to how these traits can be taken even further please comment them and I'll add them to the list!