Belgium was already used in the revolt against Austria, it was the United States of Belgium. If à revolt happen again I don't see why the name would not be taken again.
Austria would not be able to keep it, that's why it was given to the Netherland in the hope of creating a proper buffer state against France. Austria can't defend it if it find itself at war with France or Prussia or both.
I still don't understand why France start with only 3 research slots while Italy who was in even worse shape start with 4. It take age to unlock all research slots and by the time you do the game is already over.
No the common peoples themselves cared nothing for colonies and had little say in the matter, but the elites and politicians certainly did and even sometime it was the ambition of a few select individuals. Saying Europeans wanted colonies is wrong, most of them cared about making ends.
Indeed, there was a reason why the German Empire and Italy wanted colonies so much, it was a proof of a country prestige and great power statut. To lose them was a blow to national prestige and the demotion to a third rate power.
Even if Sweden managed to unite Scandinavia and keep it, it still would not be a great power, they just lack the population for it.
I can't see them managing to conquer any land in northern germany and keeping it for long.
That's what Emperor Wilhelm I said in his letter to former impress Josephine, Alsace-Lorraine wasn't taken so much to increase german territory but to weaken France.
I don't see it happening, if one tried that he would lose the support of his vassals, be forced to abdicate at best, or deposed by his own vassals or even family if that doesn't invite invasion by by neighboring countries. It's hard to even see the troups directly under the king staying loyal...