The Hussite Wars did nothing to stop Hussite religious expansion as such. What stopped it was a simple lack of understandment. Again, it was very much a national Czech movement, and so failed to meet much understandment amongst Germans in particular.
This is debatable. The Hussite Wars did of course have an effect, as they killed much of the leadership and made people think "Hmm, if I convert to Lollardy I'll likely get killed. I think I'll stay a Roman Catholic." And while you are correct that it was mostly a Czech movement, it most certainly did spread to neighbouring areas in Hungary, Poland, Austria, Croatia, and Germany.
So it is a separate church, then. Why would any ruler approve both Catholics and Hussites, in that case?
So as to avoid maor inter-religious quarrels and prevent all out civil war perhaps? It is little different than a number of principalities in OTL legalising both Protestantism and Catholicism or states in the Balkans and East Europe legalism both Catholicism and Orthodoxy.
No, it wasn't. The defenestration was an uprising directed specifically against King Sigismund's loyal officials. If king Wenceslaus is an ally of the Hussites, why would they kill what were for all purposes his delegates? Mind you, they might do something crazy like that, but I doubt that the alliance and the royal tolerance of Hussitism will survive it.
My sources give a rather different reasoning behind the defenestration, but yours sounds more likely. The event will be edited out for the next installment.
The Adriatic coastline was never too important for Venice as a sea power.
Huh? This is a new one for me. I seem to remember the Venetians in OTL striving desperately to maintain control over Dalmatia and Dubrovnik and fighting fiercely against the Hungarians, Byzantines, and Ottomans (at different points in time) to maintain naval supremacy on the Adriatic. I also seem to remember the Adriatic being the only way for Venice,
as a sea power to reach the Eastern Mediterranean. Really, that is the strangest argument I have ever heard out of you. I may be wrong though, so correct me if you can.
What of Savoy? Of Bologna? Of Estense? And of the myriad other small but still potent states and city-states in northern Italy? What of the Swiss? What, finally, of the Pope? And France and Aragon too might get involved.
Bologna is part of Florence by this installment already, Savoy is more worried with French affairs than anything else at this point, Estense is simply not powerful enough to challenge Florence, the small city states are likewise either not capable of doing any damage or brought under the power of another state, the Swiss are simply not a factor, and the Papacy has too much to worry about with the heresies and pleasing his backers to go to war in Italy. While France (and Savoy, and possibly Switzerland) and Aragon could become involved, it would be further down the line. Remember, France is incredibly weakened in TTL, and Aragon is also weaker than OTL. There will be a clash in the future, don't worry, it just hasn't happened yet.
Wouldn't say. Firstly, France had a huge surge of nationalism in OTL, numerous surges in fact, and most of them with heavy religious elements - yet Gallicanism was as far as the French took things. Secondly, by this point Catholicism had mostly taken hold in both Ireland and Scotland.
First, please note that the Celtic Reformation has not seperated from the Church yet. As for the comparison with France, it doesn't really work. The situation in the Celtic nations, besides the surge of nationalism, also involves anti-English sentiment and a growing pan-Celtic identity that fosters the transmission of ideas from one Celtic nation to another. The surge in Celtic nationalism is also much stronger than the one France experienced in OTL as the Celts are finally expressing their national identity(ies) after hundreds of years of foreign domination. And yes, Roman Catholicism was followed by the masses of the Celtic countries, but theologically this Catholicism had numerous differences from the official one preached by the Pope from St. Peter's Throne. The Celtic countries still have a much more monastic form of Catholicism, more egalitarianism, more focus on Jesus rather than Church doctrine (all things espoused by the Lollard heresies), and a more naturalist theology.