Avoiding Munich traveling from Immenstadt, Germany I to Balzano, Italy and back to Zurich

Have a look at Open Railway Map.

https://www.openrailwaymap.org

There’s another route out of Immenstadt: via Kempten, Pfronten-Steinach, and Garmisch-Partenkirchen to Innsbruck, where you can pick up the Railjet to Italy

Surprisingly, it's not much slower, but as far as I can see you'd need a lot of changes, and depending on your date, there's a bus replacement for part of it.

Alternatively, you can go in the other direction: Lindau and Lakes Constance. Again, there's not much in it time wise

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I’d avoid using Rail Planner to plan (despite the name!) Use a good timetable search such as Bahn.com, and don't be afraid to break a journey up into smaller chunks.

You should check whether a pass is worth it for these 3 days.

For Zurich airport to Immenstadt, check prices on bahn.de.

For Immenstadt to Bozen, check bahn.de and tickets.oebb.at.

For Bozen to Zurich Airport, check tickets.oebb.at.

As to avoiding Munich: that's possible, in principle, but you forgot to mention your travel dates. These are always relevant because of engineering works.

The Railjet has very nice first class. I guess it depends where else you're traveling

You can't upgrade your pass as such, but you can exchange it for a first class one.

Apologizes thought I provided enough information, but I did not.

Two of us are traveling September 14-27. We purchased a seven-day pass for the month of September for $635. It was at a discount for September, and I’m considered a senior :) 

When in Immenstadt we wanted the ability to take the train during the day while family is busy working and explore other nearby areas. Looking back, I could have probably purchased each portion of our trip separately, but I wasn’t sure. Probably all I needed a four-day pass, but the price difference seemed reasonable to add more days. Naive, I guess. 

• ralderton I appreciate the idea of another route out of Immenstadt: via Kempten, Pfronten-Steinach, and Garmisch-Partenkirchen to Innsbruck. We’ve been to these places, but as you said that’s a lot of changes and adding a bus as well. A bit to hectic for my liking. I will look into Bahn.com to see what other options I have. I think I’m going to stick with 2nd class based on not understanding the system fully. No need to spend more money yet again. I could not find a train going 

• rvdborgt you’re right, I probably purchased more than needed unless we travel three more days from Immenstadt or Balzanom. The additional days seemed better than not having them, but I don’t fully understand the rail system and prices. 

• thibcabe appreciate everything you wrote. Thanks for confirmation that I’m taking the least complicated, quickest trip based on our itinerary and dates. As you stated, I will make sure to purchase reserved seats, but I’m not going to “pop” for 1st class. 

• It’s been 24 years since we took the train from Immenstadt to Italy, but we went to Austria first then to Venice on our honeymoon. So, it is hard to remember how and what we did then, but I do know that we flew into Munich. 

• Now I need to figure out how to use the other days that I’ve purchased. 

• Thanks everyone.