@Laurarayxxx I'm on board with this one. I think it would be awesome if we could save our current/local game to a cloud library (even if that version was stripped of some of the detail) - or even create a different house for that game (would be cool if you could import your fully-developed sims - or meet with them at a public venue or something). There are many creative ways to approach it realizing the limitations.
The person who is visiting a household could have to come alone, to reduce chaos. When someone visits another house or has a visitor it's a rather goofy process currently, and you have no control over the other(s), so I think it would be more fun if someone was controlling the other party.
We all know that Sims on 'autopilot' leave something to be desired at times, so it would have to be a step up from that! (And for that matter, it has potential to be rather cool!)