Need advice on my itinerary

We are planning a 5/6 day Switzerland sojourn in the last week of May. Our family includes a 9 year old kid. We will enter Switzerland via Zurich and travel straight to Grindelwald where we plan to station ourselves for teh entire period by renting a 1-Bedroom villa / apartment.
We plan to make day trips form Grindelwald to places like Jungfraujoch, Mt Titlis, Lucern and if possible Montreux.
Need your advice on the feasibility of the day trips, specially Montreux.
Or should split our stay in two different places like Grindelwald and Lucern?
Is there any other places of interest, natural beauty, activity which we should cover form Grindelwald (in addition to jungfraujoch)?
Cheers!

Thanks Arno for your feedback. We do love train journeys. But then again, as you said, doing justice to Lucern or Montreux after 2x3 hrs train journeys is a concern.
Do you suggest then that we should split our stay between these places?
Another question I had is , is it worth visiting both Jungfraujoch as well as Mt. Titlis?
Thanks once again.
Cheers!

Hello shibatosh. For a rather short 5 or 6 day stay, I would personally prefer to stay located in one town only and make some longer trips from there. I'm not sure how important the trip to Montreux is for you. It's a beautiful train ride though, especially via the Golden Pass route, and if you leave early you will still have time to explore Montreux. The same goes for Lucerne. In all, it's a matter of personal preference. And as Arno said: there's so much to do and see in and around Grindelwald, that you will by no means get bored even if you stay put there during your entire stay.

Jungfraujoch and Titlis are entirely different, so in that sense you could easily visit both. It the train ride to Engelberg turns out to be too long, you could opt for Mt. Pilatus instead, which can be reached from Lucerne and offers great views too. If you want to narrow your choice down to only one viewing point, I would advise to up to the Jungfraujoch. It's close to Grindelwald and provides an amazing view of the Aletsch glacier (provided that weather is fine of course).

Thanks Annika for your feedback. We would like to rather stay in one location and do some long train journeys. As for the trip to Montreux we were more interested in the train journey via the Golden Pass route. So far on the 'firm' to visit list is Jungfraujokh and Mount Titlis. On the 'may be' list is trip to Montreux, Lucern and Schlithorn. I am yet to do detailed research on must do / must see for Lucern and Montreux. But a paddle steamer trip on Lake Lucern and in Montreux a visit to the Chateau do Chillon is on the cards.
We would like to keep 1/2 days free for small hikes around Grindelwald, we have a 9 year kid. Your 1 day round trip of teh Bernese Oberland also seems enticing.
I guess a 4 day 'Swiss Saver Flexi Pass' will be appropriate for us.
Your views will be really helpful.
Cheers!

Hi shibatosh. Purchasing a Swiss Saver Flexi Pass sounds like a good plan. Your free travel days could be used for your longer trips, such as Lucerne and/or Engelberg-Titlis, Montreux/Chateau de Chillon. A 3 or 4 day Swiss Saver Flexi Pass would cover these days, including boat rides over lake Lucerne. A 50% discount applies to all other days between your first and last free travel day. These discounted days could be used for your trips and hikes in the Grindelwald area. A roundabout tour in the Bernese Oberland can definitely be recommended! Please note that the Männlichen cable car only opens on May 28, so be careful when planning a trip that involves the Männlichen.

This topic on sightseeing in the Lucerne area may provide some further ideas.

Thanks Annika for all the help. I will probably again need your suggestions when I finalise the detailed itinerary.

OK, now with all your suggestions and some more research, I think I have reached a landing. We will be in Switzerland for 6 nights and for teh full duration we will be stationed in Grindelwald. Here is how we have tentatively planned the activities.

29-May Reach Grindelwald from Rome (via Zurich) by early afternoon. Relax (Free Day)
30-May Jungfraujoch
31-May Schilthorn and Trummelbach Falls via Murren
01-Jun Round about journey Grindelwald - Mannlichen - Wengen - Lauterbrunnen Interlaken - Grindelwald
02-Jun Lucerne (Golden pass route) (Short boat trip on the lake, roam around the town)
03-Jun Walking trips around Grindelwald, or short trip to Interlaken (Boat trip to Spiez, retun by train)
04-Jun Travel back to Zurich for return flight at mid day

Need your feedback on the plan. Also should i take a 4 day or 5 day swiss saver flexi pass?
Thanks in advance!

Shibatosh