Thank you Lucas. Very useful. Now i have taken your comments and amended the schedule. Let me know if this is doable!
Day 1 - arrival in Zurich at 2 PM and then proceed to Luzern by train - evening and night spend in Luzern
Day 2 - visit Mount Titlis, Lion Monument, - night at Luzern
Day 3 - visit Kapellbrücke (chapel bridge) and Pilatus - night at Luzern
Day 4 - early morning leave Interlaken - spend Interlaken sight seeing - night at IL
Day 5 - IL to Jungfraujoch - back to IL - night at IL
Day 6 - Day trip to Montreux via Golden Pass Panaroma train - night at IL
Day 7 - Morning Interlaken to Andermatt via train
Day 7 - Noon - Andermatt to Zermatt via Glacier Express
Day 7 evening - Zermatt to Zurich via train - night Zurich
Day 8 - Rhine falls at Zurich and sight seeing
Day 8 - evening fly out of Zurich
Summary - 3 nights each at Luzern and Interlaken and one night at Zurich.
I feel day 7 is packed with train journey - but hopefully its possible. Any thoughts? Is there any concern in night travel in train?
Couple of clarification - Is there a transit in Zermatt from Glacier to local train . How long it takes to transit? Is it same station at Zermatt?
We are interested to see a chocolate factory as well. Is it possible to cover on Day 6 either in Interlaken or Montreux?
Do you / know any who organise day trips to Mount Titlis, Pilatus, Jungfraujoch. I know of viator. Any other travel companies - ideas welcome.
Your thoughts and feedback on the above are most valuable.