Hmm. If it's just a custom world and it's going to start behaving itself properly now that the duplicate .world file is gone, unless I'm missing something it seems to me that the only thing to worry about is the originally vacationed household that never got through the Change Hometown procedure entirely. If you can revert and replay that bit, then you might be fine with the two connected worlds as intended. The sims themselves should be fine regardless as long as you can "reach" them, they don't seem to be the cause of any issues here.