I was looking to make a mod where the baby is not put down for ANY interaction unless the sim is directed to do so. I understand that the animations may be off but im still interested. Does anyone know how I could do this?

I'm not totally sure but my first impression is that this isn't possible in a straight forward way - I think you'd have to edit the ITUNs of ALL interactions to allow the child-carrying posture, and after that I'm not sure if all would work.

Maybe try editing the ITUNs of some of the most important ones and seeing how it goes? If you use an interaction that a sim can already hold a child for, you should be able to just copy that posture related text over.

In my list of game things to mess with, I've been wanting to look at ITUNs for the interactions you can do with a bird or baby dragon on your shoulder. It would be nice if your pirate/fantasy sim could have them out more often.

I'm pretty sure this is the same thing or very similar to making more interactions doable holding a baby.