Relocation Orders likely hood

I have two children to a father who has never made an effort, nor has be filled his financial obligations. I have a daughter who is 6 and a son who has just turned 5. He has not seen either child in the last three years and child support is not paid. He makes excuses to not see them, he favours our daughter over our son (we separated when I was pregnant). We have a history of domestic violence (financial/emotional/some physical and sexual) and a previous IVO was granted.

I've now approached him via my solicitor to work out some details for a relocation to our country of origin, he has objected - I have a child with my now husband and we want to move to be near both our families (my now husband is from the same country), financial security, a chance to buy property and an ability to further our careers.

What kinds of things should I offer up to ensure this goes ahead?

My ex husband has a knack for lying and omitting the whole truth. We've never prevented access to the children if it has been requested, but he will say we do.

I'd like to avoid court and resolve this as smoothly as possible

Suggestions muchly appreciated.

I'm not sure what I should be proposing - regular Skype calls/emails/phone calls - flying him to our homeland (he is also from there) during school holidays for visits for the first 12 months then flying them here?

Whilst not fulfilling his financial obligation am I allowed to suggest we wipe the debt in exchange for him paying for the flights?

Also if consent orders are agreed how do I make them relevant in an international court?

Money is control for him - so if there is financial gain I'm sure it would be a faster transition. I am concerned for my children's well being in his care. He has a nasty temper and sees nothing wrong with shouting for no apparent reason. The thought of sending my kids here to be with him is terrifying. I understand the "best interests of the children" act of the law - and the right to a relationship with both parent - I do have concerns about his ability to parent. If it was to go to court is there any way to predict an outcome? What do the courts usually order in these cases? - It is a very lenghty and expensive process.

Also if we were successful in obtaining consent orders am I able to put a clause in to have them reviewed on an annual basis?

We are heading to a Hague country - I think even if we weren't it would all need to be done by the book. Their father terrifies me - but that is me - there is a chance (albeit slight) he will do right by the children. They have to have the opportunity to form their own opinion of him without my input.