I think the "casual game theory" of (4) is, if you want to improve those places, let them have work visas. There are people in certain countries who can be empowered through work visas to pursue their calling (pastors in churches, teaching mathematics in universities, sizing contact lenses of the rich and idle or whatever). Those who choose not to apply for the visas will maybe try something at home, knowing they can get that work visa if what they try doesn't work. And maybe in the trying they will find a different calling than they thought. In succeeding at the things they try at home they might lower the need for work visas.