Should I learn German, Dutch, Swedish, Norwegian, or Danish?

I don't think I'd go to Twente for it, it's more of a tech institute. Amsterdam, Leiden, Maastricht or Groningen have good psych programmes. Do check if they offer a masters and/or bachelors in English.

Do check requisites.

If you are going to study in the Netherlands full-time, you will need to learn Dutch.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.