I think for them it's only about having their own constitution and sovereignty. Another one of their goals might be to stop using the Spanish language, which a big part of the population has done already.
They are perfectly fine with open borders, being a part of the European Union, using the Euro as currency, and even with keeping their Spanish passports (i.e. double nationality).
They are perfectly fine with open borders, being a part of the European Union, using the Euro as currency, and even with keeping their Spanish passports (i.e. double nationality).