Don't think that the non-HP areas of Universal are not kid friendly. I took my then 4 year old to Disney and Universal and she loved Universal. This was before IOA was built.
Some examples are
Studio Side - ET, Men in Black, Animal Actors Show, Minion and Shrek Ride, Superstar Parade to name a few
IOA - Seuss Area is awesome for everyone, Jurassic Park areas, Comic Book area is great for photo ops, The Marvel Section has big rides but the Superheros come out on ATV's and do photos.
This is just sampling. I am sure i missed a few things.