Before commenting on the interesting discussion that followed, the PoD itself:
where Boniface doesn't die from his wounds.
You mean Boniface VIII ofcourse, right? I put it to you that the exact day and age of his death would be scarcely significant; the Pope was VERY old for that time - not a competitor to Dachspmg's least favourite Venetian, but still. In any case, he was quite broken by then; his plans were crushed and so, they say, was his spirit after all that torture he had undergone. If anything, had he reigned for any longer, the Papacy would have only lost in power and influence, and would have become a French puppet; the effects would have been exactly the opposite of what you imply, as France would have been considerably strenghthened; it could have intervenned in the HRE and nipped the Habsburg threat in the bud, and I am not sure if the English would have dared move against it then.
I tend to think that most kings back in middle ages were more or less spiritual, actually (or at least tried to be)
They were, with several well-known exceptions. But above all, most of them tended to be quite pragmatical when dealing with the Pope.
Nonetheless, I do remind you that even at his strongest the Pope wasn't all that strong as people make him out to be. A notable example would be the Canossa incident; yes, many enough know of it and cite it as an example of Papal power and influence. Rather less popularily known is the fact that Gregory VII subsequently only barely saved his life with Norman help and even then de facto lost power while Rome burned; the Normans didn't care for him more than the Emperors did.
Nevertheless, I do not think that the Papacy was doomed to lose what power and influence it did have; at least, it could retain all that for longer without its internal crises. If, instead of kings and emperors manipulating the cardinals, Vatican was to play the kings and emperors off against each other - as it had tried, and with some success - it could have fared quite well. Heh, now that would have been a fun timeline, with Papacy as a Britain-like power, fighting to preserve the balance of power with the help of a mercenary army (perhaps had the Pope struck an earlier agreement with the Swiss... I really think that supporting the Habsburgs was a disastrous decision for them). If we ever have a medieval NES, someone just HAS to do that.
