Ex-husband's demands

So this is quite a long and difficult case with many different contributing factors however, I will try and keep this brief.

A bit of background info, my wife and I have been married for 4.5 years and have had 2 sons. Prior to this she was married for 6 years to her ex-husband and they had 2 daughters. When they separated, he was paying my now wife £200 a month for the girls until he decided to do a PhD which meant that his income was non-taxable and therefore CSA would not be able to take any money off him. She couldn't afford to continue living in her current property without the maintenance payments so I came on the scene, moved her to Wales and provided for the girls even though I was only being paid £3.30 as an electrical apprentice at the time. Her ex took her to court for moving away to try and get a residential order so she stayed living where she was. We offered him every other weekend and half of the holidays and he said that wasn't enough so he took her to court and ended up with every other weekend and half of the holidays and he had to travel to Wales to collect and drop off the children. However, a 400 mile round trip every other weekend was not ideal and so arrangements changed that he would stay in Wales with the girls and we were so desperate for money that we even let him stay in our house when he came down as this was in the best interests for the girls.

After my first year of my apprenticeship, my employer wasn't able to afford to keep me, so we ended up relocating back to where she used to live and I continued my apprenticeship up there. As we had moved closer again he agreed to pay child maintenance again of £200/month and then when he completed his PhD, the payment increased to £277/month. He then moved to just around the corner from us (his parents bought a house for him) and we told him that we were renting and that we had no stability and that its only a small 3 bed house and we will out-grow it soon so it's likely we will have to move. He said that he would move anyway which was fine.

Since then, our has been on the market for 6 months with people coming in to view the property which is stressful in itself but with 4 kids in the house and trying to keep it tidy whilst I am in work is impossible and it's been stressful to say the least particularly for my wife. We began searching for a new property to rent in the area for the whole 6 months and anything that came up was either too small or too expensive and even if we wanted to view the property that was too expensive, it would have already been let out by the time we'd arranged to view it.

Then, just out of interest, I thought that I would look into the possibility of us buying a house. I discovered that we could not afford to purchase anything in the area as prices are ridiculous. I did however find an amazing property that is a 4/5 bed hose in Norwich which is 1 hour 45 minutes away from where we currently live on a 50% shared ownership scheme (which makes the house affordable for us). It has a massive garden with play equipment for the children and enough space for them all to have their own bedrooms. It's in a nice location with 3 local schools, all with either good or outstanding OFSTED reports and all under-subscribed last year. However, as this is inconvenient for the ex-husband, he has once again taken us to court to try and prevent us from moving (or have full custody of the children).

CAFCASS have been involved and their report recommended that the girls relocate to Norwich with us, however he believes that some things were left out of the report. So now we are waiting for a second hearing on 11th September.

Believe it or not, that is a very brief version of the background of our situation. The situation we find ourselves in now is that in the last hearing, it was judged that there was not enough evidence regarding a few things but in particular with regard to her ex's statement that we hadn't looked properly for housing in the local area and that we can afford it!? So he has been asked to provide evidence of housing that we can afford in the area and as a result has sent us a message asking for the following information;
a) A copy of the proposed mortgage agreement detailing the costs
b) A copy of the lease agreement detailing the service charge, the rent and any other costs
c) Further details on the arrangement around travel costs, particularly with respect to fuel, between me and my employer (He is asking this because I am able to stay with my current employer and commute, however I have a company van and fuel card and so no extra costs are incurred in this case)
d) Further details on the remaining duration of my apprenticeship and my projected income for when this concludes

FINALLY, my question is...

Does he have the right to ask for these things? I know the courts have asked him to provide information regarding affordable housing but can he really ask for these things?

Any help will be greatly appreciated.