Also keep in mind that CDG-GVA flights are pure Schengen flights, as AF uses a part of the terminal in GVA which is French territory. You actually go through French passport control in GVA upon landing, to LEAVE France, and then go through Swiss passport control, to enter the Confederacy.
On the other hand, ZRH is exclusively Swiss territory.
Which means,
- no passport control in CDG2 when connecting from the US to ZRH
- passport control in CDG 2E when connecting from GVA (you entered France in GVA airport and already went through French immigration there) to the US, as you need to leave France.
Walking from one hall to another one in CDG2 involves going through immigration when connecting from Schengen to non-Schengen destinations (and vice versa). Using the airside shuttle between flights to non Schengen destinations does not involve entering France, so no immigration check.
To make the matters more simple
, the Swiss confederacy has signed a bi-lateral agreement with the EU to implement the regulations of the Schengen agreement, but this is not operational yet ... Should be simpler when it is implemented.