I want to travel on the Bernina Express from Tirano to Pontresina then to Samedan then to Chur to connect with the train to Zurich. After the Bernina what are the trains involved to complete the trip and be able to take a fast train to Paris.
the hourly regional trains cover the same route at the same speed with the same views.
Just take the next regional. And again. And then the next train to Zürich.
uh, are you planning the length of the Bernina Express plus two stopovers and a train to Zürich AND a train to Paris all in the same day?
If you don't need to go to Zürich for anything else you could take a train (or trains) to Basel and get the Paris train there. It will still pass Zürich but on some you don't need to change.