Isn't it better to just move them out, or back in again? Just wondering...

Just so you know, deleting sims could corrupt gamefiles, if you're unlucky. Actually, killing them off or moving them out is a much better alternative. If I'm not wrong, it's possible (and probably safer) to delete them from the family bin. Don't think I've done it myself, so I'm not 100% sure if it's possible.