From Vienna or Salzburge to take the Gracier Express to Zermatt plan for 6 nights in Switzerland

1. Train: Vienna or Salzburg, train direction Zürich or Bregenz or Bludenz, get out at Landeck. Austrian post bus to Nauders, Swiss post bus to Scuol, train to somewhere in the Engadin valley like St. Moritz. It may take a full day or even more if starting from Vienna, and waiting for the connecting buses in remote mountain areas may be a little perplexing. Next day, Glacier Express to Zermatt.

2. Easier but a bit less scenic: Vienna or Salzburg, train direction Zürich, change trains in Buchs to Chur, Switzerland. Spend night in Chur. Take next day Glacier Express from Chur to Zermatt, skipping the first section but still with a lot of rails to ride.

1) Should I stop at Chur for a night then take on the Gracier express to Zermatt.
2) how many night I should stay in Zermatt is 2 will be too many?
3) from Zermatt please suggest me where to see and stay for 3 nights . I I'm not sure about Interlaken or Lucerne or Bern because I plan to go to Paris from that point.
Thanks again.
Tommie

Yes spend the night in Chur. Its the oldest city in Switzerland, and has an interesting historic district.

2 nights is not too many in Zermatt. Glacier Express leaves Chur at 11:26 and 12:26 in June. That will double your chances of seeing the Matterhorn if the weather is not optimal.
Zermatt is chock full of hotels. My favorite is the Hotel Ambiance. It is one of the last hotels in Zermatt still run by its owners. Others will also have their favorites. A bit of a walk up hill, but they have their own electric luggage cart that will take you there if you notify in advance your arrival time at the station.

Muerren is as good as any location for 3 additional days, especially if you like mountains. You can get to Paris from there in 6 hours.

Thanks Sam
From Zermatt I still have another 3 nights before leaving to Paris, I would like some advise where should I base and what to see. Thanks

See my edit of previous post.

Thanks again Sam
A friend of mine talking about Interlaken, do you think it's worth visiting?

Interlaken is a summer resort town with lots of big hotels. It is the local transportation hub to visit the Berner Oberland mountains (Muerren, Wengen, Grindelwald), lake cruises on the Brienzersee and Thunersee, and mainline rail connections to Spiez and Bern.
Its not my favorite, and I think you will find the consensus on this forum is "Why stay there when you can conveniently stay up in the mountains."
Having said that, I would not discount it.