My wife and I can route ourselves from Porto to London via Geneva in order to see friends who live in Geneva. It would be a Thursday in September, arriving 4:40 pm and departing 8:50 pm (to London) with just carry-on luggage. Both flights are in business class and are on Swiss: we're U.S. citizens.

It's been years since I flew to or through GVA; I recall it being a very easy airport and having done something like this planned stop quite some time ago. But since things can change...

1. Does leaving the airport and coming back this way seem feasible?
2. Would there be enough time to head into town?
3. We always just do carry-on, but would it speed things at all if this time we checked our wheelies from Porto through to London?
4. There's a six hour connection through Zurich. I assume that it would be very inconvenient for our friends to meet us there. But if somehow it would work from their end, would ZRH be better (or, for example, is it more of a hassle because it's a bigger airport, etc)?

Thanks for any advice.