Is Pakistan a dangerous place for european citizens?

Your planned activity outside of Islamabad increases your risk greatly. There are terrorists active in the refugee settlements. Spain has troops in Afghanistan and they filed a report that ISI has assisted the Taliban in causing trouble in Afghanistan, you could seen as guilty by associate by some. Having contacts within Pakistan like you do is good but what do you know about their contacts and their contacts contacts? You would need permission from office of the Commissioner of Afghan Refugees to go to the camps and traveling to the camps and being located where they are would be dangerous. Make sure you buy a refundable ticket as you said you wouldn't go until the summer. Between now and then the security situation could very greatly.