Nationality is usually not relevant in these cases but rather where you've been in the 10-14 days before entering the country.

And have plan B ready- at the mo Austria is about every day making more severe restrictions due to the new covid/omi pandemic-it may mean you have to do quarantine for 7 or even 10 days. This also depends on your nationality and how long you stay in DE before the trip.

Appreciate the advice. Thank you. 

Several options are possible

most direct route Munich - St.Magarethen - Chur/Landquart - St.Moritz

St.Moritz - Kitzbühl i recommend to catch the EC163 Transalpin :)
St.Moritz - Landquart/Chur - Sargans - EC163 directly to Kitzbühl :)

I recommend to catch atleast once the direct trains from Chur to St.Moritz (as it´s the famous Albula Route that is even Part of the Glacier express route)

Kitzbühl - Munich i suggest 3 different Routes :D 
Kitzbühl - Wörgl - Munich (fastest Route)
Kitzbühl - Innsbruck & then directly via Garmisch Patenkirchen to Munich (pretty scenic)
Kitzbühl - Salzburg - Munich (maybe have a stopover of few hours in Salzburg)
 

Many thanks. 

What kind of help do you need?

To plan these journeys, please do not use the rail planner app (it's not reliable enough) but check the DB (German), ÖBB (Austrian) or SBB (Swiss) planners.

Reservations for these journeys are not needed.