Even bringing burglars back would be a start. I started one game in The Sims 3, and the fist night a burglar broke in. He got away, after stealing the TOILET and SHOWER. I had to wait for my (brother and sister) sims to come back from their first day of work, to be able to afford to replace the toilet.
That's another thing. In The Sims they get paid daily, what if they got paid weekly (like in real life)? That would a new level of difficulty, in that you wouldn't have your household funds increasing daily, and would have to wait for "PAYDAY", to do things. It's a small change, but it would make a difference.
As for Aspirations, I'm glad that you choose a new one after completing one. But I agree, HAVING to finish one before starting another would be good.