Good. Now you should think backwards and decide how you're going to get back to Zurich. Plane, train or car? That should help you determine your farthest destination where you'll begin the return half of the itinerary ending in Zurich or the last stop before zooming back to Zurich. I would spend at least 4 nights in each hotel and make day trips (i.e., Montreux is an easy day-trip by train from Bern, Siena is an easy day-trip from Florence, mid-Lake Como is an easy day-trip by bus or car from Lugano and vice-versa).

Personally, I think Cinque Terre would be hard to fit into this trip. Also keep in mind that most hotels in Bellagio and Varenna begin closing by the third weekend in October. There's always one open somewhere, but your choices become limited.

It's up to you to prioritize your list and decide what you'd most like to see/do.

Thanks to everybody. It looks like we are going to postpone this trip until next year so I will check back with you later if need more help.