Where did you get that information that Americans are not very popular in Europe?
Well, that may be true for some people but for sure not for whole Europe and for sure not for the Alps region.
There are always people that don`t like others. Same would be with Germans in the world.
You will be fine with English language in Germany and Austria, especially at the tourist areas.
Berchtesgaden is a good choice!
A lot to watch in that area and of the kind you would like to see.
And you would be very close to visit the Salzburgring race track, in case you wife is fine with that. But you would need a rent car to get there as it is located outside of the city Salzburg.
More via PM I think, as we go way off topic here.
Edited by Stefan Roess, Oct 09 2017 - 10:03 AM.