I think withdrawing the license on the spot serves to avert an immediate danger, be that to yourself, to the public, or both. Certainly this applies to a driver who's infuriated enough to have accelerated to 150, but not to the same driver in a calm state. Moreover, after the deed that's not even the police's job any more. So no, I doubt the license will be withdrawn at the time of the Einvernahme.
Indeed, it's incredibly difficult to actually stay silent.
For me, and probably for most everybody, it was (and probably is) much easier and thereby safer to reply each time with something like "I don't want to comment on that" or in German "dazu möchte ich nichts sagen" or "ich sage nichts". No need to change the wording, just repeat your mantra every time.
You can't avoid a "Einvernahme", you have to appear in person (under normal circumstances). Otherwise the police may come and pick you up at your workplace or at home to conduct the Einvernahme.
ETA:
As for German vs. English:
The Strafprozessordnung, the regulations on criminal proceedings which includes an Einvernahme, state that where possible the statements should be protocolled in the language they were spoken, if possible. That's not possible unless at least one person present speaks your language. So it might be useful to call them up, preferably as soon as you receive the letter, and request to be questioned in English. At the end of the questioning you'll be asked to sign the protocol, something you can refuse. You can also ask questions during the Einvernahme, AFAIK (contrary to US, and perhaps UK police) Swiss police can not lie.
Is this new? After a car accident I was interviewed in German via an English translator but the protocol was in German. My corrections of the German protocol took longer than the interview as I did not accept the German version when read back to me as word for word accurate to what I said. The translator was appalling, the magistrate's English was better. I won as the Police had clearly lied in their report.
I was imprecise, the actual wording ( §78.2 ) doesn't just say "where possible" but also restricts recording in the speaker's language to "important statements":
"The record is made in the language of the proceedings, but important statements must if possible be recorded in the language in which the person examined makes them."
So perhaps your statements were considered not important enough to warrant the effort, for whatever that's worth.
Committed what is considered a crime in SWITZERLAND ONLY, if I made an accident and caused the damage or injuries that is universal understanding of the crime.
Barreling along at +50 kph over the limit in most places around the world will probably attract the attention of the law, not just here in Switzerland.
I don't quite understand. Are you saying that you were only speeding for a very short time for a specific reason so therefore it wouldn't be considered an offence elsewhere?
For example, someone needing to significantly push over the speed limit to overtake another vehicle is therefore exempt from a speeding offence? Or am I misunderstanding something?
Yes I am glad I am entertaining you, I am also entertained by all the blitzers hidden behind the trees and that they exchange them every week (may be they borrow different blitzers from time to time), I really am so desperate at times a police officer standing on cold morning with his laser gun, but unfortunately nobody is speeding, you can read that utter disappointment on his face. So at the end of the year more flashers have to be put, in the middle of straight autobahn, which is located in the field with cows, then utter criminals will be punished! Sucking it up, bro
The initial point made, that +45 kph on autobahn is not a criminal proceeding in other countries! traffic offense by default is not a criminal act! that is the difference of Switzerland with other countries
Actually, I think you should stand your ground and argue the case. You can use this argument above, as well as the "accelerating momentarily" excuse. I'm sure the court will consider these extenuating circumstances and will be suitably convinced to throw out the case as the trumped-up hogwash it appears, so clearly, to be.
I'm from the UK and doing that kind of speed over the limit on the motorway will certainly land you in expensive trouble with the law if you are caught.
Did I write something about what I expect??? I simply replied to a person who "No sympathy, you committed a crime" that it is a criminal proceeding in Switzerland only, in other countries it is a traffic law proceeding.