I used #3 to good effect in France. I asked in French, and when I got a reply in English, I switched to Chinese and she decided French was not such a bad compromise
True, but it's one thing to expect to find people who speak English in a country, and another to expect to find a job only knowing English if you go to a country where the official language is NOT English!
The "point" you apparently fail to see is that to speak Bärntüütsch in places like St. Gallen or Schaffhausen will not help you at all but rather make matters more complicated. And Zürchers do not exactly appreciate Baaasel-Tiitsch. In Basel (one big point for those folks ) they, at least most of them are relatively tolerant, except that they feel sooooo superior above the Alsace people.
And what results from this for immigrants ? Simple. That they in the first case should concentrate on the Standard Language as the basis, and then, when having a kind of basis, carefully venture out into the local or regional dialect(s).
As soon as you in another language understand the local dialect (without speaking it) you at least have "won the battle" even if possibly not yet the war
I don't think its so simple.. whenever I asked that it seemed nobody respected that I wanted to speak german.. I lived in a WG of ski instructors in Berner Oberland. Most of them spoke Bern deutsch, but would only speak to me in english (they wanted to improve their mostly already fluent English too!). The problem came when we all had dinner: they all sat around chatting away to each other, and I had no idea what they were saying. Even when i asked them to speak Hochdeutsch so i'd understand they'd always slip back into it...
After 6 months of teaching swiss kids to ski from all over CH i can pretty much understand a one on one conversation spoken to me in most swiss dialects (nearly even grindelwald deutsch, which seems to most messed up of all..) but still have huge issues with group situations, or with loads of background noise..
OP: keep at learning hochdeutsch since everyone CAN speak it when they choose. Swiss german takes time..
Group situations in combination with background noise are a problem in all languages, made worse by people who do not care about speaking clearly, or people who are "speeding" when speaking as they primarily want to hear themselves.