Interessting thoughts on here.
Kinda confusing though.
I think anyone can apreciate a foreign visitor trying to speak their language, nowadays so many germans speak english or french though, as they learn it starting in elementary school.
I think the best thing you can do to be liked is not to assume that just because you speak a foreign language no people will understand you.
I have met americans and Brits in Germany that talked about the German people around them and then were astonished when I just looked at them and said:"Now that was not very nice!"
Then again I met Germans doing the same in America.

I am a German, who now lives in the USA. I am teaching both of my kids to speak, read and eventually write German.