Thanks Slowpoke. My comments :
<<"Day 1 - Lucerne
Travel - Take a train from Paris to Basel/Zurich & connecting train to Lucerne to reach around 3 p.m
To do - Local sight-seeing & exploring the city in evening ">>
There is excellent service from Basel to Luzern. See attached screen grab. Why would you detour through Zürich...unless you wish to get a quick look at the city? You could leave your baggage at the left-luggage office or in lockers. I am not recommemding it, only commenting. That is because, most people find Luzern more rewarding to visit for tourist attractions.
We will choose coming from Basel to Lucerne & explore the city in evening.
There won't be a lot of daylight time in the evening in early October.
Do you have specific things that you want to do in Zürich?
If you want to go there and walk the Bahnhofstrase=see and parts of th eold tow, perhaps have a meal at Zeüghauskellr, that should be possible. Otherwise, it is normally not a city tha we recommend for first time visitors. You will possibly be too late for serious shopping
Thought is to explore some part of the city as you mentioned above & may be have dinner there. It is an option in case time permits. Not keen on shopping.
<<"Will you suggest to stay in Wengen/Murren/Grindelwald etc. instead of Interlaken to get mountain village experience?">>
Absolutely. You will, of course be further from Interlaken and the train connection to Zermatt, but the trade off is a good one, in my opinion.
During October, the between-seasons break is beginning, so a few restaurants and hotels - far from all of them - will be taking a break. More toward the end of the month. Thee can be lovely clear days in the Alps. However, the weather is very changeable:
Which one will suggest for staying out of these towns Wengen, Murren, Grindelwald, Lauterbrunnen etc.?
2 nights or 1 night in one of these towns & 1 night in Interlaken?
<<"What are the major attractions in Engelberg? How much time is required
to cover it? Is it possible to cover it along with Mt Titlis on the same
Not sure what "... to cover it... " means.
How much time is required for a trip to explore Engelberg?
Can Engelberg be covered on the same day along with Mt. Titlis ?
For Travel through Swiss pass - 3 days pass X 2 to cover the entire 6 days - Is it possible to have 2 different passes for 6 days ?
Does the itinerary seem fine other wise? Do you still consider it to be hectic/busy?