This seems to be along dual lines for you OP, your rights and the rights of your children. There is whatever the CSA is now, and quite honestly, that needs to be revised into being much, much harder. So that takes care of your children, but it sounds as if you're wanting some kind of 'alimony' for yourself.
If your ex partner isn't a decent man then there's nothing that will change that. Look on it that at least you aren't married to him and take some consolation that he's nothing to you personally.
If I were him and I had millions in the bank you wouldn't be worrying about a car repair because whether you still love somebody or not, they were something to you once and money - when you have it - isn't a difficult fix. Have you asked him?
Regarding your campaign I would have to say an emphatic 'NO'. There are enough daft people who carry on wearing blinkers, having children with men who will not support those children. Before a woman is pregnant she has all of the power... after that, not so much. The very least a woman can do is make sure that the legal side is stitched up so that financials are secured.
That said, there are some really smug women about, feeling safe in their married states, as if their husbands will never leave them and will always want to see their children. That's a knife edge right there. Men do leave and they do neglect their children, if they're that way inclined. Married or not.
I would really support a campaign to make women very, very aware of how vulnerable they are if they rely on men for security. The law also needs changing there - SAHM should be a paid job and errant fathers should be legally prevented from fathering more children if they don't provide for the ones they have. On that point, I would support some medieval reinforcement involving rusty shears.
Sorry OP but women have to protect themselves and stop being so dreamy. Marriage never had a hint of romance when it was enacted, it's just evolved that way to make it a money-making exercise. The bones of it are cold, hard cash and control of women.
The only happy marriages, in my opinion, are where there is perfect balance and neither party is dependent on the other, they are together because they want to be and choose that path. All the rest are examples of fakery and living on a precipice.