Hello CaptainCab, I'm sorry for this position you are in, as taking the kids to church on Friday night and Saturday needs to be agreed upon by both parents, but your kids may not want to go, especially if it's forced upon them.
My twin and I were told to go to Sunday school, but we never did, instead going to the park and kicking a football.
What else is happening is she has said you can visit the kids as long as you pay 50% of the medical bills, doing this is reasonable but not when it's used against you in this manner, I'm sure you are more than happy to pay for whatever, but not as a way like this.
Some breakups are sensible in the conditions outlaid, but there are times when you are told to do whatever suits her can be unreasonable.
I think applying for a Parenting Order is a good way, especially when your kids want to sleep over at your place and not be forced to do anything that they may not want to do.
Just be prepared for any extraordinary claims that are made against and wish you all the best.