Thank you both of you for suggestions. That's good suggestion of combining Stoos with Rigi. I have added it to my itinerary. You are correct that pilatus is 50% off for STP. Instead I will use that much money in Matterhorn.
please find below my revised itinerary (I have also considered the closures at some places)
26th April (Will use STP) (Half-Day)
Arrival on Zurich Airport at noon. Will take train to Interlaken and checkin to Accommodation.
After settling luggage, will do Lake Brinze – Aare Gorge – Unterseen – Interlaken
27th April (will use STP) (Full-day)
Interlaken, Wengen, Kleine Scheidig, Jungfraujoch, Grindelwald to First Cliff Walk, Wengen, Interlaken
28th April (Will use STP) (full-Day)
Interlaken, Wengen, Murren, Schilthorn, Piz Gloria, Thrill Walk, Gimmelwald, Stechelberg, Trummelbach, Lauterbrunnen, Wengen, Interlaken
29th April ( will use STP) (full-Day)
*Interlaken, Zermatt, Matterhorn, Spiez, Interlaken*
30th April (will use STP) (full-day)
Will check out from Interlaken and go to Lucerne.
After settling luggage, will do Burgenstock - Kehrsiten – Burgenstock resort - Lucerne (Lion Monument Chapel Bridge)
1st May (Will use STP) (full-Day)
Lucerne - Engelberg - Mount Titlis – Lucerne
2nd May (Will use STP) (full-Day)
Lucerne, Schwyz, Stoos, Brünnen (cable car), vitznau (by boat), rigi kulm, rigi kaltbad, weggis, Lucerne.
3rd May (will use STP) (full-day)
Will check out from Lucerne and go to Zurich. Will do round trip of Rhine Falls and explore Zurich.
4th May (No STP) (Half-Day)
Zurich - We have flight by noon. Hence will relax and packup.
Please suggest me if any improvement is required.
However, I am still missing following, plz suggest me where should I add it.
1. As per Rockostyer, Golderpass will be closed. I am going to Zermatt but I won't be able to use Glacier express because of its timings. Any chance of using any Panoramic train at any of the day or do I need to spend separate day for it?
2. I am still not sure where can I add visit to Chocolate factory. Plz suggest a good place.
3. Can I carry food (ready to cook packets, home made Indian breads etc.) with us to Switzerland? Any restriction in this?