I have several recommendations for game mechanics.
Labor/Living Wage mechanics
It cost a lots of time to jump between cities to raise wages, it's getting annoying when you have 5+ cities. It's also kind of tedious to click a lot when changing wages by occupation.
The interface should be able to apply every wage change at once. You change every job by typing it or clicking up/down button, then apply it. It also need to have options to apply it in the city or the entire region. The living wage and labor should be under one menu. Here's what I have in mind:
Cloning buildings
The cloning buildings should stop producing colonist when Immigration is blocked, and do the opposite when Immigration is allowed. By doing so, you only need one switch to stop colonist coming to your city. Powering it off or selling it when not needed confuses my estimation for the jobs/colonist count. Maybe the cloning facility should produce some research when not producing colonist?
Production priority
As posted by Redeye1973
here, there should be an option to apply priority to every building in the city. I want to add that there should be an option to apply it in every city.
IQ Statistics
IQ stats should be displayed in distribution graph like age stats, to better estimate how many colonist is able to take a certain job in a building.
Feel free to correct me if there's a trick to solve these problems, or if you have better ideas.