You're going to love it!
If your hotel reservations are still flexible I'd highly recommend picking 2 places to stay - you just have too much packed in with not enough time to savor what makes these places amazing. You could spend all 6 nights just in one of these places and not run out of things to explore and enjoy. We spend our summers in Murren and have explored all around Switzerland...you can't choose a bad location, but you just can't see it all, especially in 6 nights and you risk not seeing the best of it by rushing.
An example of the logistical issues of staying somewhere for 1 night - take Zermatt for example - say you wake up on day 4 in Murren and get on a train around 10 am. It's going to take you around 3.5 hours via train to get to Zermatt. You arrive in Zermatt around 1:30, check into your hotel and do dinner. Then the next day you need to get to do the Gornergrat but you also need to get to Lausanne which is another 3.5 hours away...so you're going to need to wake up early, check out of your hotel, store your luggage at the train station, rush to the Gornergrat (which is always packed if you try to go early in the day), rush through in a few hours (no time for exploring the different stops/hikes along the way), get back to the train station to do another 3.5 hour train ride to arrive in Lausanne to check in for a late dinner. It's doable but it's going to feel rushed and probably a bit overwhelming.
Another issue with rushing through places is that you're counting on perfect weather the whole time. You allow 1 night in Zermatt and it's cloudy and you can't even see the Matterhorn? That's going to be a major bummer. You will have spent 20% of your trip getting somewhere and basically just seeing shops, because if the Matterhorn is in the clouds there is nothing else to see there in terms of nature.
You can get the lake feel of Switzerland in Luzern, Lausanne or by just staying extra time in Murren and doing a day trip down to Interlaken/Thun (Lake Brienz/Lake Thun). Lots of great little castles and cute villages on Lake Thun's boat trip. That way you don't have to waste half a day changing lodging.
Consider potentially doing the Schilthorn in place of Gornergrat/Zermatt if you're just going to Zermatt for the Gornergrat. It's not the exact same, but it gives you epic expansive views and is very convenient to you already staying in Murren. Zermatt is a great car free village if your priority is souvenir shopping, but it's VERY VERY touristy. Like hoards of people everywhere. And while the Matterhorn is obviously beautiful, the views in the actual town of Zermatt aren't really anything.
Any feedback on these hotels?
Hotel Edelweiss in Murren has amazing views, make sure you get a mountain view room.
Any restaurants or coffee we shouldn’t miss?
Pension Gimmelwald (if you like beer, try the beer they brew there)
Should we do the travel pass or half fare card for this itinerary?
This really depends on what you end up deciding to do. Use sbb.ch to price out your travel legs (the website typically auto posts 1/2 fare not full fare, so account for that) The Swiss Travel Pass isn't super great in Murren, but you can price it all out to see.
To get from Mürren to Zermatt is the bus our best option or a longer train route better?
Bus is never the best option. Train is always best. You can get up and walk around and enjoy the views instead of being stuck in a seat on the road the whole time.
Anything else as first time Switzerland travelers that we should keep in mind?
Enjoy! It's the best place on earth :)
