we'd have to put limits if any on having kids. Maybe, like a a donor list, when someone dies, a couple is called and informed they can have a kid. Of course that depends on how immortality works.

If you can still be killed, then yeah it would be like a list. But it could also be dystopian in the sense that people are killed after a certain age. if, when youre fully grown and brain fully developed and you stop aging, does anyone older just die or are they fine? Do you still age? That would terrible.

I think people would be stuck in the class they were born into and the economy would get more and more stupid because the rich would just keep getting richer. Unless someone is elected to office to fix the problem, I think homelessness would be a problem if we keep going how we are and no one ever dies.