Euro Global Pass in Switzerland.

It does not cover the train(s) from Interlaken Ost to the Berner Oberland destinations, but it does give a 25% discount. Same with lifts in the Berner Oberland. It does cover boat rides on the Thunersee and Brienzersee, and a discount on other Swiss lakes. Buses are not included.

Italy is problematic, as you must purchase seat reservations on high speed Trenitalia trains and IC trains, and it is not valid on Italo trains or the Circumvesuviana trains around Naples.

“Ease of purchase” and “ease of use” are two different things. It might help to know more specifics on where you plan to be within the various countries to determine which pass, if any, would be best for ease of use. Euro rail passes are often not recommended due to the requirement for seat reservations. If you’ll be spending time in the Berner Oberland area (highly recommended), you’ll want a pass that gets you where you want to go. The cable car fares add up very fast.

We plan to fly into Geneva and spend 8-10 days in Switzerland with plans to exit the country via the Bernina Express Line to Tirano. Our focus in Italy will be Northern Italy and the Alps. We think renting a car is best for this portion of the trip (about a week). We either pick up a car in Milan (after seeing the Duomo), or Sondria, Italy (skipping Milan).
We plan to fly out of Vienna, Austria, Again loose agenda with focus on smaller villages and mountain passes. I know that a car is easier on this portion of the trip as well.

In considering this agenda, it seems like the Eurorail Global Pass may not be the best for us, as we only plan on 3 countries. I'm leaning to purchase the 8 day Swiss Travel Pass, but just pay point to point for the other countries.

Another question a little 'off topic': When you board busses, say in Italy, and you don't have an inclusive pass, do they usually prefer to take coins, or can you use your credit card? (Sorry a basic question but it's been awhile since we went and used busses).

Thank you for helping me think this through.

The only time I have taken buses in Italy, I bought tickets in advance. You should post this as a stand alone question on the Italy forum where more knowledgeable people will see it.