I had the same issue of incorrect setup when I first had the cs's fitted, I then had them redone which was a huge improvement but still think they need some fine tuning.
Insurance would be minimal I think due to it being a safety feature but I suppose on the other hand they may see it as your pushing the car to the limits to warrent needing one. It's definitely on my to do list at some stage but at £2500 fitted I need to start saving my pennies or persuade a few owners to join a group buy
There isn't much more to mod on you car so can see how it's slowing down
but yeah the responsibilities and finances have to take priority with the little one, wait till you start taking him for junior karting sessions a whole other money pit for you to go through