you should get the policy as early as you can, and keep it on at all times. meritocracy (what you can choose when activating the policy in addition to growing the bureaucracy) will give you a % based boost on certain levels (20, 40, 60 I think). If you start as a republic you will start with much higher meritocracy, making it a lot easier in the beginning to get enough required governance. Republics typically have land owned by the citizens, which means you have to have governance for 100% of the development. However, if nobles own the land you might get a 30%-40% autonomy minimum in the province but you might not need almost any governance for the province. So if you want to expand a lot and don't have the governance, try to "give the lands to our nobles" whenever you conquer a province to not have to govern all of it yourself.

Okay, thanks for the reply, I'll keep it in mind. ^^