we fly into Zurich at 8AM in Aug. (family of 6) then to Lucerne, Lugano, and on to Italy. Should we jsut take train to Lucerne from airport or spend the night in Z? We have 3 days in Switzerland, as Italy is our main focus.
Agreed.
Don't stay the night in Zurich.
If you feel like you're really robbing Zurich, then spend 2-3 hours. From the airport it's a 15 minute train to the main train station. You can get cash, get oriented, and whatnot there -- then it's a 10 minute walk to the old town of Zurich. Spend a couple hours there, then get on your train to Lucerne.
I might lean toward spending a couple hours in Zurich just to stretch my legs and get outside for a while before getting onto the hour long tran ride -- if it were me.
Head straight to Luzern. There are direct trains at the airport, and it's only an hour away.
On to Lucerne just an hour down the tracks. We did that with our family and managed to squeeze a half day of sight-seeing in before we crashed at our hotel. Enjoy.