traveling from Berner Oberland area of Switzerland to the Cinque Terra area of Italy

You have several flight options. The general feeling on this site is to fly direct to Europe and make your connection to Zurich. In this case Delta out of MSP to Amsterdam (AMS) and then to Zurich. Several good flights that will get you to Zurich before lunch.Then catch the train to Berner Oberland.
Delta also has a flight out of JFK non stop to Zurich. But if you miss this connection you don't go until the next day out of JFK. Out of AMS if you missed your connection there is probably aflight in an hour or two.
And the general feeling on this site on the return flight is to get a direct-to-the-USA flight. In this case there is a non stop Milan MXP non stop to JFK then a connection to MSP. There are two flight out of MXP to JFK (on the date I picked in September) one doens't leave MXP until 1 PM. This COULD allow an early morning train from C.T. to MXP rather than spend the night near the airport the night before. I will let others comment if this is a doable idea.
If you connected to a flight from Europe to MSP you would have to leave MXP on an early morning flight and need be in Milan the night before.
(I think Delta does have a non stop Pisa to JFK but only during a couple of months in the summer.)

Other posters may have some other ideas and routes for you to consider.

The train trip between any two towns in the BO and CT regions takes a full day (8 hours with 3 connections from Lauterbrunnen to Monterosso, more to/from other towns), but that is our preferred way to do it. How to Look Up Train Schedules and Routes Online gives you the DB train schedule link and tips for using it. Most schedules are currently published through June 13.

Going home from the Cinque Terre, Pisa, Genoa, Florence, and Milan are the closest airports (in that order). Milan Malpensa (MXP) has nonstops to the US year round; Pisa PSA has flights to the US on a few days a week in the warmest months; and Florence FLR, Milan Linate LIN and Genoa GVA do not have nonstops the US.

However, since even Minneapolis is not served by nonstops from Milan, to get home you'll have to change planes anyway. Thus, you should try to get a flight from Pisa or Genoa, assuming they don't leave too early. If the only options leave too early to make it from the CT to the airport on the same day, you'll have to overnight near the airport the day before.

A tip: on Kayak http://www.kayak.com/flights, if you put in "PSA,GVA,FLR" (without the quotes), it will search Pisa, Genoa, and Florence all at once.

I agree that if you have a choice, it's better to change in Europe than the US. Minneapolis has two flights a day to Amsterdam on Delta, where you should have good onward connections on KLM to Zurich, Pisa and Florence (a quick look on the Wikipedia page for Amsterdam airport shows that there is no service from there to Genoa). You could also fly Air France or Delta from Minneapolis to Paris CDG and connect with Air France to Zurich, Florence, Pisa, or Genoa, but connections in CDG are more difficult than in Amsterdam.