Determining how much child support should be paid?

Hi there, I currently live in Alberta, but lived in Richmond BC when I got divorced and filed my separation agreement and divorce with the BC courts at that time . Currently FMEP in BC is involved in collecting and paying me child support from my ex husband.My ex husband gave up his permanent residence in BC prior to me moving away from BC and since then works in the NWT for 6 weeks on and then for his 2 weeks off comes back to BC where he stays with his girlfriend. He does not maintain a permanent residence.
I have 2 kids (14 years and an 18 year old who will be a fulltime university student).
Our separation agreement stipulates that child support will be paid for each child while they are fulltime students and if not fulltime students until they are 19.
I currently live with a new partner- however we have maintained separate finances. We do co-own a house 50/50. There are no other joint accounts and we share expenses 50/50.

My ex husband has requested my new partners T 4 information. Does he have a right to this information and should it be considered when determining how much child support should be paid?
My ex husband earns about $80,000 per year. I make slightly more than this and so does my new partner.