3. If every citizen could have maximum one child, would the population stagnate?

Each person only having one child would result in a static or even declining population (over the long term). There would be fluctuations especially if there were three or more generations of a family alive at any one time, but what you are talking about here is just a replacement level of childbirth.

However, this doesn't take into account those that die before adulthood or before they could find a partner and mate - accidents will still happen. Given the environment and the tasks that you've thought up for people, accidents are probably more likely than now. Nor does it take into those who choose not to have children.

You'd probably have to allow couples to have more than two children if you want to ensure a stable population.

3. If every citizen could have maximum one child, would the population stagnate?

Each person only having one child would result in a static or even declining population (over the long term). There would be fluctuations especially if there were three or more generations of a family alive at any one time, but what you are talking about here is just a replacement level of childbirth.

However, this doesn't take into account those that die before adulthood or before they could find a partner and mate - accidents will still happen. Given the environment and the tasks that you've thought up for people, accidents are probably more likely than now. Nor does it take into those who choose not to have children.

You'd probably have to allow couples to have more than two children if you want to ensure a stable population.

Given that there seem to be plenty of resources available - from the scavengers etc. then one of the pressures for having many children - which is having someone to look after you when you are old - is much reduced, so couples might not want to have more than 2 or 3 children anyway.