No, Cutting immigration to nothing would be horrible for long term future of the country and incentives for not having children I don't believe would be effective and if you took away tax credits for children it would just result in more children going hungry because they have parents who cant afford to feed them.
I do wish there was a way to incentive people who cant even afford to take care of them selves from having children but I cant come up with a single way that would both work and be ethical.
making women pay child support just like men and give them the same punishment if they don't pay it (jail time).
I want to point out that child support laws are gender neutral, it is completely base on child custody and income. I work with a man that receives child support from his ex-wife. Both Woman and Men can get jail time for contempt of court if they refuse to abide by a court order to pay child support.