However, needs must when the Devil drives. And the Low countries are very vulnerable if there is an internal revolt and a hostile ( even if secretely ) emperor.... Maybe an eventual separation of the Habsburg lands different from OTL? With the Low countries going to a Habsburg which can get support from the dutch Protestant. There's also the question of the Habsburg Alsace lands.
Hm. If Germany (together with France) goes officially Lutheran, it could well be that the Netherlands also become Lutheran, and not Calvinist. I think such a big boost for Luther could indeed strangle Calvinism at birth. By adopting Lutheranism the NL would seperate politcially from unliked Burgundy-Spain, while ankling for support of the Emperor...
Now, Ferdinand was fairly open to Protestantism, but hes only governor in Austria, not Burgundy-Netherlands. And I cant see him become it (and later rulrer in the Netherlands), really: Charles has no reason to support such, as it would reduce his eprsonal power, and Francis has no reasn to support such as he wants the Netherlands ideally seperated from Habsburg.
Yes. But there is the english exemple ( and the wealth of the Churhc to be put into the King/Emperor coffers, which is a big temptation.
You have that with Lutehranism, too. Luther explictly stated the monarchs should be heads of their states church, which was why Lutheranism became so influential in Germany

Of course, the question at least in Germany then becomes to whom money and land go: The Emperor, or the territorial princes?
Ouch. That will not make for compromise or tolerence.
Its a possibility, but then... apparently, politcial pressure was enough for Landgrave Philip to adopt Lutheranism, to have an united protestant front. Political pressure in the form of the Emperor and Saxony breathing down his neck could have the same results ITTL. Though South Germany, with its patchwork collection of hudnreds of ministates - I could see several of them becoming Zwinglian. IOTL, Landgrave Philip was more or less teh spokesperson for the Upper German cities inside the Schmalkalden League, and hence could influence them to stay "with the party line", so to say. But heres no Schmalkalden League, so the cities will all go their own religious way...
Actually, not Zwingli, but
Martin Bucer would most likely lead this from Strassburg, but he was mostly Zwinglian. After Zwingli and Luther failed to find common ground, Bucer tried to stay with Luther, but this failed, too. Here, he might instead seek concordance with Zwingli, and find it. Might even be he leads the Zwinlian movement after Zwinglis death... then again, he apparently genuinly dislike dthe protetsant infighting, so he might try to stay on Francis and Luthers line. Given how he eventually didnt even IOTL I doubt this, though.