1. The rank III that gives you FIVE FREE POPULATION points in your new colonies. Once you get that, you don't need to put people into colony ships anymore.
2. Culture flipping. 'Nuff said.
3. Rank V research: FREE five research points for each of your colonies. Think about that.
The key is to use the rank III FIVE FREE POPULATION ability to colony spam. In the early game you do NOTHING except build colony ships and shipyards. Once you colonize enough planets, you'll get BENEVOLENCE research rank five and you won't need to construct a single research building. To win, you just build constructors and culture flip everyone (another benevolence branch).
I wrote in another threat how to use these abilities to become very, very overpowered very quickly.