Thanks Rockoyster for nice suggestion again:
My planned Itinerary is as below:
12th May: Arrival in Zurich, visit of Rhine falls, Limmat rivr and Lake Zurich small round trip(ZVV 9 o clock pass)
13th May: Bernina express trip and back to Zurich (Savers Day Pass)
14th May: Arrival in Lucerne, Mt. Pilatus golden round trip, Lucerne city sightseeing (SHFC)
15th May: Mt Titlis excursion (SHFC)
16th May: Mt Rigi trip, travel upto Brienze by train (with luggage), from Brienz to Interlaken by cruise, Bern trip from Interlaken (after check-in) (Savers Day Pass)
17th May: Wengen, Jungfraujoch, Grindelwald Trip (SHFC)
18th May: Oberhofen castle visit, Lake Thun Visit, Lauterbrunnen, Murren Visit, Harder kulm Excursion (SHFC)
19th May: Departure from Interlaken, visit of Spiez in morning, travel upto Geneva by train (via Zweisimmen, Montreux, RdN).
20th May: visit of Geneva in Morning and Departure to Paris on 14:29 train.
I hope above clarifies and it may kindly be noted that every question I asked in one or the other forum of this beautiful website is/was relevant to my planned itinerary.
Thanks for all your beautiful suggestions so far.