You could call the realm Frank's Democratic Tyranny of the Kingdom of Evilstani, and it wouldn't be a Democracy, Tyranny, or a Kingdom. It still says "republic" in the only place that counts, so far as game mechanics counts.
The difficulty has nothing to do with it. There are lots of things that are easy to do, that are not done due to the policy of non-interference in the game, except in dire emergencies. Heck, every time someone loses a region, or a unit, or even a point of honor due to a bug, it's all a matter of seconds to fix it. But we don't. We play through it.
This situation is no different.
I personally don't consider letting the realm go into anarchy to be an abuse. If I did, I wouldn't be suggesting it. It seems to me to ba perfectly legitimate way in which to peacefully change your government style. Just refuse to participate in the government. It collapses, you reform it as something else.
If someone steps in and takes leadership, then obviously not everyone wanted to change. At that point, since he's the government, you can legitimately rebel against him (should be pretty easy to win), and reform however you want. Sounds like no matter what, you win and get your new government.