Being more selective will result in more intelligent and efficient workers. Efficiency rates can vary between 50-150. A good starting point is a 50acceptance rate and AQ's and DQ's of around 100. Topias and Ports are also regulators of the work force. Topias house your work force and need to be monitored, so that new ones can be built or existing ones upgraded as they become filled.
Ports hold large amounts of angels and demons.
They're good to lay down when there's trouble involving workers who need to be reduced in a hurry. It's tempting to alter technology, since it increases population over time, but the higher the technology the greater the threat of nuclear war. High technology levels are best countered by increased peacefulness on the planet. Disasters will impact heaven and hell frequently. Floods, earthquakes, and similar events will lead to the rapid influx of souls into the afterlife.