@Inthelivinfor
Now that you're in China, perhaps you could take a look at China's long history - NOT to emulate how China integrates it's conquered populations (or in the reverse, how Chinese respond to invaders), but to study the strategy and tactics of war - to include passive war.
I'm not too familiar with the Basque separatist movement, but I do know it's been going on for quite some time. The head-on approach hasn't been working and will probably never work - based on western and central European politics - it usually just results in increased oppression, increased security, etc which is absolutely fantastic for politicians, as it gives them cause for increased taxes and oppressive, finger-pointing, inflammatory, scape-goat Hitler-esque style political agendas.
Protests are great to understand the magnitude of the popular movement - but it won't resolve the separation issue.
I've found that the ideal passive solution is to become such a foul stench - that they'll rush the separatist vote through the assembly.
As an unrealistic, but plausible example - utilize the Spanish infrastructure to engage in massive public works projects, social employment projects, etc ad infinitum, then default on the debts. At this difficult point in time - Spain can neigh afford another massive debt default - by pushing the region out - Spain would potentially be able to write off the debt default and pass the responsibility to your new state (as a condition of separation - although I'm sure they'll try to pile on other debts as they jettison your state).
I recall that Basque dominated region sits on one of Spain's borders - historically, these buffer zones are strenuously protected and retained by the parent state.
Japan used Okinawa as their buffer during WW2 and the Okinawan people suffered egregiously.
However - a change in tactics is surely called for - violence is oppressed and a separatist vote will always be defeated by the majority unless they're motivated. Study your enemy well (Sun Zi), understand their and your strengths and weaknesses (SWOT?), and maximize BOTH to your advantage in a controlling manner (Taiji), but the solution must be win win - but you'll be controlling the many battlefronts (location, economics, etc) along with the timing. This requires Herculean strength, patience, and endurance - but I know the Basque people group as a whole has all of these attributes - as they have remained fiercely independent as a concentrated people group, along with retaining their own language, identity, and customs.
Wish you the best and congrats on an excellent supportive turnout. The arrest of only 8 people out of over 100k is a phenomenal if not miraculous show of peaceful resistance.