No, developed countries aren't facing the challenge of hight birth rates, instead, they are facing problems like: corruption, bad policies, and lack of infrastructure along with conflict from other countries or within their own.
He basically said "It's all good in the hood. We just need to chill, we ain't got no problem. Nothing here to be scared of."
Try asking one question at a time
That the constitution gave too much power to the federal government. Anti-federalist wanted individual states to have power over the government due to fear of a tyranical government