I just don't find your arguments for separation tell the whole story. I support self-determination but ultimately the strongest argument for independence is that Catalonia has a population of greater than several EU states and could go it alone without federalism.
You mention oppression under Franco. He hated and executed a bunch of people, from anarchists, to PSOE under Largo Caballero, to hard core communists. Other language minorities were not allowed to spread their language either. That was 40 years ago. Do you really blame the rest of the country, today, for the 'sins' of their grandparents?
Old wounds and if your hatred is for "Madrid", they were Republicans - NOT bullfighting fascists.
Galegos and Basques would have equal claim to independence under linguistic autonomy. But I guess I see bilingualism as a blessing rather than a curse. And in that regard the Catalonian government's educational policies have been undoing the historical trauma of Spanish as the "High" language of diglossia. Yet Valencia isn't calling to become a separate country, despite Valenciano being a near-identical language.
I'm not condoning the actions of PP, Rajoy or the Guardia Civil by any means.