Hi Freshstartin2015,
What is your question exactly?
If you are asking whether it is best to let your ex husband control the situation, then that is really a personal choice/preference. If I were in your position, I would take an active role in the financial agreement and not let your ex husband dictate terms. However, it really depends on what type of person your ex husband is and what your relationship with him is currently like.
In relation to what should be considered in your financial agreement, the answer is that all jointly held and individually held assets, including gifts and beneficial entitlements are included in a "shared pool" and can be divided between he parties. Your husband's income level, relative to yours, will be considered. As will the fact that you have been a stay at home mum for four children. Further, any future custody arrangements will be considered (i.e. who will be the primary caretaker) to determine who will share more of the financial and emotional burden from raising the children.
If you are asking what you should do, given your ex husband is not responding, then the answer is, attempt to negotiate with him further, if he is still being uncooperative, you can apply to the Family Court for a financial order and/or a parenting order.