In reality, it was rather Portugal that was dragging Spain into its wars.I don't understand how your POD could have changed Europe so much, but I fear that many of the thing described here are not plausible. For example the centralization of the HRE and extinction of the Electorates is something that would unify Germany against the Emperor and foreign intervention would abound even more, that is why it would not even be considered by the Habsburgs. Giving Netherlands away just after they were reconquered also makes little sense for Spain. Portugal doesn't need to move against Spain if Spain doesn't drag them to their wars.
It turns out that the British and Dutch decided to forget that Portugal was supposed to be their ally and moved to attack and seize their comparatively poorly defended (compared to Spanish) colonies.
The origin of the secession was that Spain began to get fed up with having to pay for the defense of Portugal and asked them to contribute to the war effort, which was apparently so intolerable for the Portuguese nobility (How dare they demand that we pay for the defense of our own colonies!) who preferred to spend triple financing a war of independence.
Of course, London and Amsterdam were delighted with this because it allowed them to grab more land from Portugal and to trap Portugal with onerous loans.
Although since we are talking about the neighbors, how is the rest of Asia taking the fact that Japan has fallen into the hands of the Kurishitan?
Are there any exiles on the Asian mainland claiming to be the rightful ruler of Japan?