Question: Is there anything you can do, outside of Racial characteristics, housing, and cloning center, that changes a planet's population growth rate in MOOII?

Not that I recall, but you can send pop to any planet as long as you have the transports. I do recall Uni Antidote or something that increases growth rate if oyu get that tech.

http://masteroforion2.blogspot.com/2005/09/growth-formula.html

Thanks, guys. The formula link is pretty comprehensive.