I quite liked the idea that Switzerland's UA could have something to do with making anyone that declares war on them absolutely miserable (like huge unhappiness hits, automatic denouncements, loss of delegates, stuff like that). Of course it would be ridiculous to make it impossible to declare war on Switzerland, but it makes sense to make you really not want to do it. True, if you are going for a domination victory and you see Switzerland, you may have to reconsider how you play that game, but I can't tell you how often I have had to stop what I'm doing and default on science or diplo because I was going for domination and I saw Ethiopia in the game. I think they could have a unique building like the Swiss Bank (naturally) and as for their other unique it could be anything.