I can't speak to all the German minority communities, but I do know a bit about the German community in Romania, whose population was around 745,000 in 1930. Nearly 64,000 Rumäniendeutsche joined the Waffen-SS voluntarily, most of them after the beginning of the Second World War (most of those who survived the war fled Romania).

An article I read from the Free University of Berlin attributes this partially to economically discriminatory policies coming from Romania's central government in Bucharest. Andreas Schmidt, the political leader of the "Deutsche Partei" (the fraction party that represented German interests in Romania at the time), was an SS member and very popular within the community, which remained influenced by a (somewhat outdated) ethnically German culture .

If you're interested in that particular community, I recommend reading the works of Herta Müller, who grew up in Romania, wrote extensively about life there, in that community, and received the Nobel Prize for Literature. She certainly sees a connection between the Romanian-Germans and Nazi ideaology.

Source (German-speaking): http://www.oei.fu-berlin.de/geschichte/soe/rezensionsseite/rezension62/index.html