That’s basically the perfect answer already. I just want to add that OP might want to prefer a city with a university as they are usually even younger and more progressive than others. While I haven’t lived in Freiburg, it certainly would be a good choice if you value that.
Yeah, but you can still chat with them on the insecure messenger. You can have both on your phone.
What would be the win if signal would support sending messages to WhatsApp? You’d still be putting your trust into meta.