You are not going to be able to take him off of your insurance until the divorce is final. This protects you as well.

Legally, he can be on your insurance. What happens if he needs major medical care? The two of you are still married. The hospital will come after you. And your stbx would have a claim to have you pay the portion that the insurance would have covered if you take him off before the divorce is final.

I would put a freeze on the credit card that has both of your names on it. This way neither one of you can increase the balance.

It does sound like you need a court order spelling out who pays what.