[quote=@Lucidnonsense]
Soooo how long could I survive as a nation of heretics? Would everyone declare crusade against me at once? Perhaps I could play some kind of heretical religious order hiding in the shadows rather than a single nation.
Also what would be the closest equivelent of Kabbalah in this setting? or should I just make up an occult belief myself.
[/quote]

Publicly, not very long. :lol Every Fiorentian nation has Ambrusian administrative offices, and garrisons of knightly orders that answer to the church. The religion is a deep-seated and pervasive one. That said, there may be a few maverick nobles that practice occultism in secret, or hedge witches that consort with magic in the deep of the woods. If a king should be branded a heretic, then he would be excommunicated, and the knights militant in his nation would likely maneuver to wrest control into direct Pontifical hands. Of course, the closer one is to the Pontificial States, the more prominent the Ambrusian influence will be.

That said, anything could happen - if multiple nations were to go heretic at the same time, who knows how the ensuing civil strife could affect the western world? If someone creates a Martin Luther character and creates a movement to rival the Ambrusians, the kingdoms could very well be plunged into a war of religion. 

You're free to do with your nation as you wish - but remember, every action has an equal and opposite reaction!