A few other suggestions:
1. it would be nice to have a building that harvested the human capital (call it an office if Harvester is too dark haha). this could be slower than clicking on individuals but would keep you from having to jump back and forth as much and also would keep you from miss-clicking and removing something from the planet's surface.
2. it could be cool to have time delays on making different resources. so small plants do less Oxygen but grow faster. Mountains take a while to erect, et al...
3. ways to alter the orbit could be a fun "late game" addition!