I suppose I could put specific activities related to those sims behind doors which are locked and only assessable to those sims, and also place their beds in there. Some things really annoy me, for example, the video game volume on computers in the sims is FULLBLAST EVEN WHEN ZOOMED OUT, so I usually do not by a computer for my household because sims have this desire to always play pc games. However, I want to make a writer for example, I could put a pc locked into a room only they could access, and they would probably never play pc games [because of how I built them]. Same with painting easels and inventors tables.
Right now I put everything into a huge "activity/living/kitchen" room. Guess I can make several smaller rooms. Still, being able to left click something and limit who can use it would be nice. Such as clicking a stove and saying only x person can use it. so other sims don't burn the house down. All of my sims have a strong desire to make waffles and burn the house down.