So how do I get just a few sims in the family to go to their owned business lot? I'd like to leave pregnant sims, kids and teenagers at home, but they all insist on coming along with the owner when he drives his car to his lot. Does groups handle this too?
Yes -- you have the main sim ask the sims you want to go along to form a casual group 'just for fun' (so you don't have to deal with the scoring thing). Then have the main sim call the taxi or click on the car to 'drive to community lot', and you'll get the choice for just that sim, or his/her group. Pick the group, and they'll all pile in and go.
Just remember to dissolve the group when they get back home (click on each member while the main sim is active, and chose 'ask to leave group'), or the group members will continue to follow the main sim around everywhere.