If I was designing a multiplayer sims option, mostly I'd limit online content to building and maybe CAS. I'd put back in a world building tool and let people work on a world cooperatively (building and populating), and post whole worlds to the gallery. Most of it would be friends only, because every online game attracts jerks and they'd run around vandalizing stuff.
Playing sims together sounds like it would be fun for maybe five minutes, for me. Young players might use it as a way to just hang out, so I'd keep it limited to friends only version of option 3 if I was including that, with the types of interactions that would be abused disabled in multiplayer. I would most likely never use it unless my granddaughter had it and wanted me to play with her.
