I agree this question should be reopened.
As you said, this is information that any HR professional in Switzerland should know. If this question were asked about the US, I think it would get lots of immediate responses.
To respond to IDrinkandIKnowThings's answer,
1) it is a shopping list question
I disagree. A shopping list question asks for suggestions of products, ideas, etc, with almost no restriction. The number of possibilities in a constantly changing market is going to be near limitless. These questions are also highly opinion-based as there is no single correct answer.
This question does not fit this definition. By asking about legal restrictions, it is asking for a limited set of codified rules and regulations. I would not be able to go create a new product tomorrow that would add to this list. To ask the opposite, for questions that are allowed, would be too broad IMO.
2) It is based no beliefs that are not backed up by reality.
You yourself said it - it is a very common misconception that it is illegal to ask these questions in the US, but that is because use of these questions can been used as as evidence of actual illegal activity (i.e. discrimination). It is completely understandable that the OP would think this, and it doesn't at all change the premise of the question. If a US company asked these questions, I would seriously question the company's ethics and the legality of their hiring practices. The OP then essentially asks which questions would be similarly unacceptable in Switzerland.
Monica also makes a good point in her comment:
A good answer will correct the OP on that point while also (of course) answering the question about Switzerland.
People will get things wrong sometimes - if they knew everything they wouldn't be here asking questions. As long as the misinformation doesn't completely invalidate the question, then just correct them and answer the question being asked.