Question 1: See here
https://www.digitec.ch/de... , otherwise ask customer service if this also applies to this model.
2nd question: It depends on your needs and whether you use 2 SIM cards at the same time... For example, private, business, travel, etc.? If the answer to this is no or rarely, then you are welcome to save yourself the hundred francs.
Question 3: That is correct. Either you use one SIM card and microSD or you use 2 SIM cards. Don't forget you have 32GB of internal memory. Do you really need that much memory? You can make a compromise sometimes.