Do you play with whims on? How would you improve them?

First, they should fix those already in the game. There are pet-related whims that keep appearing even when you no longer have a pet in the household. Whims added in seasons that keep reappearing regardless of the sims' interests (buy bee box/water balloons etc.).
Then, to add whims for all the past packs where they make sense.

Only after that, they could actually start building on it - which would be welcome.