Just wrong. You believe you're right - but there are laws that decide about right and wrong. What supreme court do you mean - the Spain one or the German one? As far as I know this case wasn't yet in the EU court. Take it to the EU court - let they decide. Until the case isn't there, he is in the charge of our courts and protected by our laws. I means thats the principal of being in one community - called EU. Otherwise someone could be hunter over different nations just because someone (Spain) feels the person it is looking for doesn't get the penalisation it deservers. That would be stupid.
What we have to win? Well there are human rights and national laws - every human being is actually protected by these laws. I think its better to obey laws instead to ignore them. There is more to loose if we didnt follow these rules.
Again, its not your interest and not your decision - also it actually doesn't matter what the majority thinks its right. Being right or not is the hands of the courts. Your example with the terrorists just lacks rationality. And I am pretty sure we Germans would be fine if you deal with him, because majority trusts in the courts decision (imho).
If you feel there is so much wrong feel free to move to another community and be more happy there. I am happy to live in the EU. There are many difficulties every nation has to work on - and the community has to work on.