Okay here's my take on what is being asked of you:
Extracurricular activities: I would pay these but make her provide you receipts for all of them so that she just doesn't arbitrarily hit you up for expenses that she may not actually be valid. I have a daughter who is in competitive gymnastics which has significant fees and expenses that I split 50/50 with my STBXW. These expenses include apparel wear, i.e. team uniforms, warm-ups etc. After all these things are also for your kids and really when it comes down to it if you don't then you end up with your XW possibly telling your kids "Sorry Junior you can have a team sweatshirt because Daddy refuses to pay for it." Plus look at the economics of it - $17 for half a sweatshirt vs. $200+ hour legal expenses to fight it.
Child care. I'm not sure what state you are in but many states factor child care costs into the child support agreement. This is something I would get some counsel on from an attorney before I agreed or disagreed to pay.
