Congratulations on your baby. Mine are 7 and almost 5 and in some ways I miss the baby days, despite the extra work.
It's good to know that you've separated to stay safe.
We have lots of resources to the right of the board and at the top. BPD communication tools are in Lesson 3 at the top of the Improving Board. It's a lot of material, but we can take it in pieces.
Like christening/baptism. Whose hesitancy is it, more yours or his? It might be best to take the lead on this one. I've personally found that by being consistent it helps. That is, sometimes making a decision (in a non-shaming or blaming way), removes the stress from a person who has trouble making decisions due to their tumultuous emotional states.
For example, despite 3 years of my ex being anxious about which school the kids go to (saying a lot but doing nothing), I took the lead in registering both of them. It's not without frustration though.
At this point, even though you've moved, the custody is still equal by law. However, you are leading here. Parallel parenting is also an option, though you are still in a leadership position at this point.
I know this is a lot to throw out there. A good first step may be improving communication. It can help. It doesn't mean being a doormat. Asserting boundaries on a healthy way is part of it. Take a look.
https://bpdfamily.com/content/listen-with-empathyhttps://bpdfamily.com/content/values-and-boundariesThis is just a start. We have a lot of material, and seasoned members who can help guide you however your situation progresses.
T