On the 8th day we will travel to Austria and be there 5 nights. On day 6 in Austria we will travel to Germany (Munich) for 2 nights.
It is not clear precisely which train JOURNEYS you will be making within Austria - or even where you plan to arrive in Austria from Switzerland.
I rather suspect that a Global Eurailpass will be a large waste of money.
Swiss Rail Pass: Maybe. (Disclaimer... I am no expert on Swiss Rail ticketing.)
It SOUNDS like you have four journeys within Switzerland, then a final journey through Switzerland into Austria (somewhere???) So maybe you are in the market for a Swiss travel pass "flex" for 4 days.
https://www.sbb.ch/en/leisure-holidays/inspiration/international-guests/swiss-travel-pass.html
And for the journey to Austria, you might purchase a point-to-point ticket if the cost is less than buying a Swiss pass for 6 days (no 5-day pass is available.) One type of p2p ticket is the supersaver fare... details here:
https://www.sbb.ch/en/travelcards-and-tickets/tickets-for-switzerland/supersaver-tickets.html
You should do some comparisons between p2p ticket prices and the rail pass option, keeping in mind whatever savings you might get from the rail pass on boats, lifts, etc.
https://www.sbb.ch/en/travelcards-and-tickets/tickets-for-switzerland/supersaver-tickets.html
GERMANY: Will you start from Salzburg? If so, a simple day pass bought at Salzburg station will get you to Munich on the regional train: The Bavaria Ticket. If not.. p2p fares from any town in Austria to Munich can be found here...
www.oebb.at
Or here:
https://reiseauskunft.bahn.de/bin/query.exe/en