I agree with both of those statements, but that's not my point. It seems like there is a cleavage on the left between Green/Pirate types and Linke types similar to the differences between Santorum & Romeny Republicans.
From what I can tell from this side of the Atlantic, the sort of people who vote Green/Pirate are educated & younger, with higher incomes. Supporters of Linke seem to be poorer, less educated and from the former East Germany.
I just don't see the young professionals who support the Greens/Pirates going all Eurosceptic. They're too cosmopolitan. One can certainly lean left and be Eurosceptic, but I have yet to see that particular kind of leftist be Eurosceptic.
Well, your assessment of the Pirate voters is partly correct. According to a recent study, the average Pirate voter is 34 years old, healthy and well educated, but poor and with a high degree of job uncertainty. The Linke voters are actually wealthier than the Pirate voters. Maybe (some of) the Pirate voters could be described as modern bohemes?
I do think you're right in estimating that they won't be too Eurosceptic, and the study shows that their voters generally have many foreign contacts. From what I've read it seems like the Pirates are generally opposed to the austerity measures in the EU and the way they have been agreed upon. Their main suggestions are for more democracy and transparency with more power to the EP, and the Council turned into a second chamber.
The study can be found at this link:
http://www.zeit.de/politik/deutschland/2012-09/Piraten-Waehler-UmfragePress at the "Die Parteien und das Wählerherz"