How does World Conquest work in 1.8?

Over the past few days I've been trying a World Conquest run, keeping my infamy low by protectorating everyone I can, and cutting the Great Powers down by making them release nations any time they got involved with me.

However, when I was ready to start my high infamy wars, I discovered that liberty desire increases a LOT based on overlord infamy. Suddenly all of my protectorates were demanding increased autonomy.

I reverted to a save before I went high infamy. It's now 1884, I still have some time. Do I let my infamy go down to 0 and annex my subjects then go high infamy?

Should I have been focusing on annexing subjects from the start instead of collecting as many protectorates as possible?