Hey Spuds.. how much difference do you think there is between tax in Geneva and taxes in Zurich?
Swiss Germans working in Geneva.. yeah they speak french quite well but alot of them also coordinate in German between themselves...
If you are not employed by Skyguide I don't see how you are in a position to make comments as you do. I worked there and seen many fail and mainly because of language barriers. I am not saying french or german has to be your first language.. what I am saying is that you gotta have a REAL good knowledge otherwise you are waisting your time.
Just for information, those who "learned" french to get by are not that well received in Geneva because even though they can "get by" it's still not great and socially some if not most of these people don't fit in. I can think of only 1 who really fit in well after he learned french but his wife was french and he was really dedicated to learn it.
It's up to you, take the chance, quit your job, and give it a go.
Another thing that most don't consider.. is social integration.. Although you can "get by" in Switzerland on english it makes for alot better of an experience if you can speak their language.