Switzerland newbie itinerary + car vs train

The Swiss train system is a marvel of efficiency and user - friendliness. I highly recommend using the trains and forget renting a car. Car rental, gas, tolls, and parking are all expensive in Switzerland.
I would suggest a modified itinerary-
Go straight to Lucerne from the Zurich airport, it's very easy and 1+hr. Lucerne is much more charming than Zurich.
Interlaken is a commercial transit center, not a quaint village. If you're going to Switzerland, don't you want to be in the Alps, and stay in Launterbrunen, Wengen, or Murren? Bern is nice, but it's not being in the Alps.
If you're going to northern Italy, perhaps take the fantastic Bernini Express to Tirano, Italy, then onto Lake Como and/ or Milan.
Perhaps review the posts under the Swiss section here on the Forum.
Have a wonderful trip!

https://search.ricksteves.com/?button=&date_range=2y&filter=Travel+Forum&query=Switzerland+car+or+train&utf8=%E2%9C%93

I agree with the first reply. Switzerland has an amazing rail system, and it would be very easy to reach all the places on your list via train. It will also likely be a faster and better way of getting around, as no problems with traffic, parking, etc.

Were you planning to stay in Interlaken? Most here (myself included) would recommend going another 20 minutes to Lauterbrunnen and staying in the the valley (gorgeous mountain scenery!). Everyone here has their favourite home base there. I prefer Lauterbrunnen, but others like Mürren or Wengen.

Were you planning to continue driving into Italy? That presents some additional issues, as there are some potentially expensive caveats to be aware of. For example, each driver will require the compulsory International Driver's Permit, which is used in conjuntion with your home D.L. There are also restricted zones (ZTL) in many towns and each pass through one may result in hefty fines! There are also some caveats to be aware of when travelling by train in Italy, so it would be prudent to do some research on that.

You may find it helpful to pack along a current copy of the Rick Steves Switzerland and Italy guidebooks.

Finally, it appears that you're planning one day in each of the destinations you listed. That won't leave much time for actually seeing anything. A bit more information on your plans would be helpful.

IMO there is no need to rent a car, as the train system is phenomenal. You are also spending a lot of precious time, moving from place to place. Is there a reason why you want to spend two days in Zurich? I would echo the previous poster's suggestion that you immediately take the train from Zurich to Lucerne. I would also suggest that you spend more time in the Jungfrau region of the Bernese Oberland. Instead of staying in Interlaken, take a look at Wengen or Murren. Both of them are charming, car-free villages. On our recent visit, we chose Wengen, as there is was some construction in Murren at the time. I'm not sure of the timeline for the completion of that work. I have no experience with Bern, so am unable to speak to keeping that as a base.

As others have said, use the trains. A car will just be an expensive headache for your trip.

Also, is there any reason you are returning to Zürich on day 6? If you are going to northern Italy from Interlaken, the logical option in my opinion is to head south, not north to Zürich.

Yall are legit incredible for your insight so far! Here's my thought process as a total noob (so any more insight is welcomed):

-This is for our anniversary, so we want to see a lot, but also relax. I work insane hours and so does my wife, so we want to be present. We LOVE being active, hiking, and delicious food - partying/nightlife aren't our thing and we dont drink.

-we'd be heading to Zurich on day 6 to catch a flight to Venice - we figured it would make the most sense to do an hour flight when otherwise it's a massive train ride (there's a whole nother segment on Italy I could do but I wanted to nail this down first.

-we like to stay in one spot for the hotel (i.e. not bounce from hotel to hotel with all our stuff) - we figured since everything is so close, maybe Bern was the move? It's not an absolute, but we have no real reference point on this.

-We figured Zurich was a cool place to explore for the day - the first day is when we show up so we would be jetlagged like crazy and half asleep, and then the next day wake up, train (we are big fitness people) and then go to Lucerne when we are awake.

It sounds like the train system is WAY easier than a car, but looking stuff up, the Swiss pass for unlimited rides was double the price of a car...per PERSON. Like $700 for 4 days per person, vs a car was $350 for the whole trip. that was part of our hesitation, plus the requirement to be at a train station at a certain time vs just picking up and going. We've driven in Santorini and the UK.

Based on your suggestions, we definitely will swap Interlaken for Lauterbrunnen, no question at all. I dont know much about Wengen or Murren. I'd love thoughts on a 'home base' (if its worth even having one).

I am so grateful for yall - let me know thoughts!

https://www.swiss-pass.ch/swiss-pass/

The Swiss Travel Pass covers boats, trains, and many lifts. In Lucerne, STP covers the boat and cogwheel train to the beautiful Mt Rigi summit.It's amazingly convenient, and for the last few years, there have been sales early in the calendar year. In most areas, the train stations are in the center of town, right where you want to be.
Don't forget how expensive gasoline, parking, and tolls can be in Switzerland. Many villages are car- free zones, so the rental will be sitting in a parking lot.
Swiss trains run frequently to most all locations. You don't do much waiting for a train.
STP shows $448 for eight days per person; 15 days $494 each. Perhaps the Half- Fare pass would work better for you.
Enjoy your time in this beautiful country.

Our trip focused on Lucerne and the Bernese Oberland. After researching which mountain excursions we wanted to take, the most economical option for us was the Half Fare Card and the Berner Oberland Pass. https://www.berneseoberlandpass.ch/all-in-1-ticket-bernese-oberland/ The pass is discounted if you have a Half Fare Card; the validity of this year's pass begins on April 1st. We found second class to be just fine for all of our train travel in Switzerland. Our home base in the Alps was Wengen and we thoroughly enjoyed the Hotel Edelweiss.

-we'd be heading to Zurich on day 6 to catch a flight to Venice - we figured it would make the most sense to do an hour flight when
otherwise it's a massive train ride (there's a whole nother segment on
Italy I could do but I wanted to nail this down first.

This doesn't make sense. If you want to explore Zürich, add that extra day in the beginning of the trip since you land in Zürich. That will save you a bit of backtracking and changing location. Then in the end, take the train from Berner Oberland to Venice. Yes, it will take a bit over six hours, but taking the train back to Zürich to fly to Venice will not save you much (if any) time. And in addition, there are some great views of the Alps from the train.

It sounds like the train system is WAY easier than a car, but looking
stuff up, the Swiss pass for unlimited rides was double the price of a
car...per PERSON. Like $700 for 4 days per person, vs a car was $350
for the whole trip. that was part of our hesitation, plus the
requirement to be at a train station at a certain time vs just picking
up and going.

A pass for unlimited travel is very expensive and probably a waste of money for your trip. There are other ways of buying tickets. And also keep in mind that the cost of renting a car is only part of the cost of driving, you need to pay for fuel and parking as well.

You can forget about cheaping out on a Swiss trip, open your wallet early and often. But it's worth it.

Trains are the way, period.

As for "I work insane hours and so does my wife, so we want to be present. We LOVE being active, hiking, and delicious food - partying/nightlife aren't our thing and we dont drink" and given it's an anniversary, hire a travel agent! Give them a laundry list and let them do the work.

Travel & Leisure and Conde Nast Traveler magazines have lists of agents on their websites. Don't sweat the trip.