Probably, yes.it would be Portugal who would separate from an alternate Brazilian Empire (basically Brazil + African Colonies)
That was more of Portugal's fear than Brazil's. The Brazilians didn't care that much when the royal family went back to Portugal. What they really wanted was simply equal representation. It was an United Kingdom, and both countries still had roughly the same population, so they should be equals.The main problem I see is that no one wanted to feel like the "tail of the dog", thus both the Portuguese and Brazilians wanted to be head of the Empire.
Meanwhile, the portuguese elites wanted to return to the colonial model, when Brazil was completely subservient to portuguese interests.
Well, Portugal considered that as an strategic and important region even before the change of capital (the amount of times the portuguese tried to take Uruguay and the platine base is surprisingly high).An Empire located at Lisbon probably wouldn't care about Uruguay, or the Platine Basin in general
Yes, that's sure. A lusitan empire with a capital in Brazil wouldn't have to deal with the same existential threads European Portugal did, for they would be in a safer position, so at most they'd try to be stay far away from European conflicts so their European territories don't get threatened by other country.And an Empire located at Rio, probably wouldn't care about European
You are only kind of right. Brazil was actually more connected to Africa and to the portuguese colonial empire than Portugal herself. Angola, specially, acted as an extension of Brazil, to the point where some communities there even tried to join Brazil when she became independent.or even African affairs. So probably not Pink Map
However, an intact United Kingdom of Portugal, Brazil and the Algarves would be much more focused on protecting their current borders than expanding it, because, without Brazil leaving the empire, there would be no drive to regain any prestige or riches, because they didn't lost anything. That is, unless the later rulers of the empire get very ambitious.