Gaul was conquered in 10 years. The conquest of the Iberian Peninsula took a bit more time. The Romans disembark in Ampurias in 218 BC and Agrippa and Octavian conquered Asturias when the last one was already emperor, in 29-19BC. Than means that they took 200 years to conquer it!
Yes and no, he is loosely based in a real general of the same name: Maximus. I am not familiar with the details. Read it some time ago, even before the movie. If I recall well he lead a revolt after the dead of Marcus Aurelius, and I don’t think he was from the Iberian Peninsula.
Not sure if I understood right. Castile and Aragon are the core of the Spanish kingdom since the marriage of the Catholic Monarchs in 1469. As a matter of fact, until than the Portuguese were also considered Spanish, since Spain had the same meaning of Iberian Peninsula. So in the beginning of the 19th century Catalonia was a part of the Spanish kingdom.
Yes, silver but also gold, cooper and iron. A metal that didn’t exist much in the Iberian Peninsula was tin, necessary to make Bronze. Since Proto-historic times it seems that it was imported from the British Islands.