I would love to see a cat teaser, or a chew toy a Sim can keep in his/her inventory, and pull out, autonomously (particularly for the Sims with specific pet oriented traits) so they can play with the pets.
I would have also liked it if cats had their own trait, "Loves or Hates the Outdoors." I think that makes perfect sense for a cat to either love outside, or prefer being inside. They can get the "One with Nature" moodlet or the opposite.