Here you are Gunny, if that is your real name:
Spoiler Alert, click show to read:
There are a handful of filler states thrown in inside of the Empire's borders, which you should be able to identify easily enough. White spaces within the Empire are small, relatively unimportant states that couldn't really be represented on the Victoria II map and white spaces outside are pretty much the same. IE - In the Balkans there's a big chunk of white space that would probably be inhabited by Croatian tribes.
Just keep it in mind
Losing another war, and/or other states don't like the emperor
What would "the right time" be?
Unless you do it at the right time, or have damn good allies
I'll pass, in that case.
EDIT: On converting that is, not the whole game.
I made it an option to convert your country, but then have to fend off massive hordes of enemies