#3 is not specific to Germans, it depends mainly on the audience. The more technical it is, the more likely it is to generate non-trivial and meaningful support requests.

Also the fact that you don't sell at discount likely filters out the bulk of self-entitled users that tend to stress support with trivia.

And your summary is 100% spot on - catering to a more savvy audience and aggressively culling other users is a good way to keep support manageable (and even pleasant!)