Thank you for your question
My name is Clare
I shall do my best to help you but I need some further information first
How old are the children and what time do they actually spend with their father?
Have you kept a diary note of this?
You need to record that into a diary - and keep it up.
When do you intend to move?
Do mean to get an old diary and record the missed ones that you remember as well as ongoing issues.
You do not have to give him the Birth Certificate - if he wants a copy let him get one.
Since he has Parental Responsibility you are under a duty to consult him on the schools - which you have done.
Now you can go ahead and make the applications for the schools of your choice.
If your ex objects then he will have to apply to the court for a Specific Issue Order so that the Court decides which school they will go to (and given the history you have nothing to fear from that)
However there is also the issue of the contact - and you may wish to consider whether the children are benefiting form the current arrangements - and the frequent cancellations and whether or not you need to make alternative arrangements - via the court if necessary
Are you going away in the near future?
Have you re-registered them at the Doctors?
Are you willing to start the court process if necessary?
What he is doing is abusive to you and the children
In the long term you need a Prohibitive steps Order to prevent him changing doctors without informing you (or at all)
and sorting out a contact arrangement that he will actually stick to
You also need a specific issue order to determine where they will go to school
The starting point is for you to attend a Mediation Information and Assessment meeting with a Family Mediator.
It is unlikely that mediation is suitable in these circumstances (of him being a bully) but you need to have attended one in order to go to court - so make an appointment as soon as possible.
Please do not let him bully you any more - you are being reasonable and he is not and you need an Order stating that the children live with you for your security - and theirs
At worst you might have Shuttle Mediation - where you are not in the same room - so please do not worry