I don't think anyone can give you a description of the whole process that will apply to you. Each case is different and each judge has their own mind.
Outcome is also a secret.
But basically - a judge can order anything at anytime. He/She shouldn't for example give full residency to your ex on the first hearing - but they can.
Okay now for generics.
First hearing judge is going to only know what has been submitted. He says you say. Judge will say I don't know - so should order some background stuff. CAFCAS in england/wales. These in england/wales are people that will go at talk to you/him and investigate other relevant facts etc. From what I have read - they can be useless to very good. (sorry).
They will produce a report - maybe recommendations. You goto court, argue a bit more, perhaps accept somethings, perhaps ask for others.
Generally if a judge feels contact should go ahead, he/she will phase it in slowly. They will want feedback also, and phase in some more.
Eventually assuming all smooth, you will get to a point of either agreeing or having a proper court hearing - experts witnesses etc.
Then a decision will be made. You can appeal (I think) and drag this on and on.
Also during the standard parts, you can argue and disobey and drag it out and out.
The judge will keep hearing and ordering.
Timeline - don't know. I think its 6-12 months. However where things are not going right, I've seen people talking about years.
On you violence - have you got proof ? I would start preparing all the facts, witnesses people who can testify. Try to get a solicitor (good one) and some good people to listen and bounce things off. Sometimes you get people around you saying things that make you feel good - but will come across in the legal system as a controlling/freaked out/hysterical mum.
Also on the abduction worry - any proof - any threats? I presume you have their passports? If he visits less than once a year, the court is not going to say here you go alternate weekend now. He has to build up some relationship. Where does he stay, what is to keep him here?
These are things you need to start writing down, and then get some good advice as to relevancy and strength.
I am in the middle of my own court action. I know the anxiety it causes. In your case double so.