Let's just say: I am Danish, exercising treaty rights in the UK, where I live with my Russian wife. My wife has a UK Residence Card due to being part of my family. Switzerland require a visa (free and quick but annoying).
Two questions, can we fly to Geneva (will the airline let us board) without a visa (only usual docs)? Do we have to exit via the French part of the airport?
When arriving in Geneva on an international flight, you are not able to exit directly to France, but will have to go through Switzerland. Exiting directly to France without going through Switzerland is only possible if you arrive on a flight from a French airport.
Is it possible to exit directly from the French side when arriving on an international flight without passing through Swiss territory?
No, you must pass through Swiss territory from an international flight.
So if it is right that your wife needs a visa to enter Switzerland, she will not even be allowed to board the plane to Geneva without having one. Depending on what is less inconvenient, you will either have to get her a Swiss visa or fly to a different airport in France.
