Yes. Having children is a moral obligation to God/society/family/etc.
No, they are free not to have children. They don't have to answer to anybody
Not if they have reproductive problems.
Yes, even if they have reproductive problems. They can adopt, you know.
They should get a medal for lowering world population.
I don't know.
If the "ex" was an ex-wife rather than an ex-girlfriend, that issue should have been discussed at length and resolved before marriage was even considered. When you have a marriage where one partner wants children and the other does NOT want them, it usually leads to divorce down the road.