Regarding napoleon i agree thats why i said he used the wrong means.
I'm not sure what you mean by "used the wrong means". What other means could he have used?
Papacy for most of its existance wanted to spread religion, thats about it, they didnt want to create a one unified entity of people just one religion, nor were intrested in creating some kind of holy christian super empire because it would have been a threat to the pope itself.
That "holy Christian super empire" existed; it was called 'the Holy Roman Empire'. And the Popes did
see it as a threat to their temporal power, which is why they ultimately destroyed it in all but name. The Medieval and Renaissance Popes saw themselves
as the 'rightful' rulers of Christendom, not the kings or emperors. In fact, this failed attempt at unifying Europe under their spiritual and temporal rule saddled the Church with the Papal States and put them on a collision course with the rising tide of European (especially Italian) nationalism in the 19th century, which almost sank it for good. The Roman Catholic Church only survived into the modern era by letting the Papal States go (at gunpoint) and by finally abandoning once and for all any lingering ambitions they may have had to exert temporal power in European affairs.
A lot of strong feudal states had a habbit of defying the pope, so they didnt wish that to happen. Regarding the holy roman empire, emperors of the empire knew about that, specially Barbarossa, thats why they were threatened by the church.
Indeed, which ultimately led to the decline into comical insignificance of the Holy Roman Empire.
"Politics is the art of looking for trouble, finding it everywhere, diagnosing it incorrectly and applying the wrong remedies." - Marx (Groucho)