I've got all the Expansions and couldn't play without any of them. I have changed the Imaginary Friend settings in the mod to 100% chance of my new babies getting an Imaginary Friend.
BUT
I feel the need to repeat what has already been said -
DO NOT accept FREE VACATION. Occasionally it does work as intended and you can get a false sense of security - but mostly it breaks the game.
Apparently even the modders haven't been able to fix it so it is broken. Totally broken.
I am always wary of sending children to boarding school too. But then I fixed that problem to my own satisfaction by building my own boarding school and rotating my young sims through it and teaching them skills while they are there. That includes all the young townies. It gives them all a chance to get to know each other and makes for a much more interesting game. My boarding school does not require generations as I built it myself.
Enjoy whatever pack you get.
Happy Simming