Re: Seeking independence
The unification under the Catholic Monarchs was a personal union. There's no reason for it to have been a trigger for the principality of Catalunya to demand independence from the Crown of Aragón. The trigger which at least some of the independence wings point to is the War of the Spanish Succession (1701-1714), following which the Crown of Aragón was dissolved (its components largely supported the losing side) and a more centralised Spanish Kingdom replaced it. But to say that they've been seeking independence since then would be incorrect: what they sought at the time was the restoration of what nowadays we would call a federal model.