I think it would be really cool to implement a system in which sims can build habits and create autonomous strings of action. For example brushing their teeth after they shower, washing their hands after they use the toilet, cleaning dishes after eating, doing homework when they get home from school, doing laundry, kissing/hugging spouse before they leave for work, etc.
Additionally, sims could build bad habits like being mean, not brushing their teeth, leaving garbage and dishes, not putting laundry in hampers (which is too easy right now since it automatically goes into the closest hamper even it is 3 rooms away), playing on their phone autonomously whenever they don't have something in their queue. Maybe this could be based on their responsibility or maybe there could be a Habits option under Slice of Life where you could assign them specific habits.
I think it would be a really good addition especially with the dirty hands and teeth that were added in the recent update. I feel like it would add some realism and flesh out their personalities even more. <3
P.S. I love your mods, it is awesome that you spend so much time on them and share them with the community, they improve the game immensely <3