Looking for some advice for July itinerary

I see that Rick Steves suggests Pontresina as an alternative to St. Moritz. Thoughts about this?

If you accept what St. Moritz is, a luxury vacation spot for the international jet-set, then it's enjoyable. If you expect some kind of Swiss cultural cliché, like happy brightly-dressed peasents making cheese and blowing Alpenhorns, then prepare to be disappointed. The setting is pretty stunning.

Similar idea with Zermatt. If you accept that it's a world-famous tourist destination and not a folksy mountain village (although they still farm in the area), then it's a great place visit. I've been all over the Alps, but I've not yet seen scenery more awe-inspiring than the high peaks of the Pennine range that tower above Zermatt. Note, though, due to the physical orientation of the lower slopes and line-of-sight geometry, you can't really appreciate this until you ascend high above the town. The majestic Matterhorn and Monte Rosa are clearly visible from the town (weather permitting), but the views really become something special once you ascend upwards.

After further thought and more research, I have decided that we won't head to St. Moritz on this trip. It is just a bit out of the way compared to our other planned visits, and I don't want to spend so much time of our 8 night trip sitting on a train. Instead we will substitute going back to the BO. We stayed last time in Wengen, and will probably do so again. Here is an updated itinerary, does this seem realistic and not too hectic?

7/4 - Arrive 10 am, train to Wengen
7/5 - Wengen/BO
7/6 - Wengen/BO
7/7 - Travel to Zermatt in morning
7/8 - Zernatt
7/9 - travel to Montreux or Vevey in late afternoon or morning depending on weather in Zermatt
7/10 - Montreux or Vevey
7/11 - Montreux or Vevey
7/12 - travel to Bern
7/13 - leave from Bern directly to ZRH airport for 10:45 am departure

Personally, I would choose Vevey over Montreux, especially if you're there to attend the jazz festival. Vevey is far prettier, much quieter, and not as squashed up against the hills and the freeway. It has a lovely old town center, a gorgeous promenade along the lake, and great restaurants. You can easily take the train from Vevey to Montreux for the festival; they are very close to each other. We were there this summer during the festival and Montreux was crammed with people. Fun to go to to hear music but wouldn't want to stay there.
If you want to see a castle, there is a beautiful one built right on the lake in Montreux called Chateau Chillon. Well worth your time! If you drive east of Lake Geneva you will come to Valais, a long valley with many castles in various states of repair and ruin. One of my favorites is in Leytron, a beautiful little village. There is absolutely no one there and they have built a breathtaking steel staircase in the remaining tower and you can climb to the top for the beautiful views overlooking the vineyards. There are also vines planted inside the ruin so it is very picturesque! Another one that is spectacular is in Sion. It is partially ruined and partially intact. The chapel is the thing to see here...they have uncovered murals on the wall that date from the 1300s and are as bright as the day they were painted. On the adjoining hill, there is a church that is just as old and has never been restored. Stunning murals, ancient graffiti, and the oldest working pipe organ in Europe. Sion itself is a beautiful little medieval town. All these are on the way to Zermatt so if you plan to drive you could easily make a day of it.
Gruyere is and easy drive, just north of Vevey about 40 minutes. You can visit the very touristy cheese museum and visit the equally touristy medieval hill town. We thought it was fun!
Zermatt is certainly worth it if you hit it on a clear day. Be prepared to drop lots of $$$ though. Between parking in the garage in Visp, riding the train up to town, lift tickets, and food, you will pay. That said, it is an amazing place to see. Not just for the Matterhorn, which is stunning, but all the other peaks, glaciers, and views that can be had. If it's clear make sure to get an early start riding the lifts up because the clouds tend to roll in when the afternoon arrives.

Thanks for your thoughts! FYI, we will be traveling by train, which is always our preference. Should have made that clear.

Add another day in Zermatt. Weather is always a roll of the dice, and if you only budget one day, you risk losing that entire day to cloudy, overcast skies. Particularly for Zermatt, which isn't easy to reach, you want that payoff of the view of the Matterhorn and Monte Rosa. Only one full day doesn't give you enough of a buffer.

Thanks Tom. As budgeted we would have 3 days and 2 nights in Zermatt (I would hope to arrive by 11:00 on the first day and drop luggage at hotel, all of day 2, and could hold on departing to Montreux or Vevey until late afternoon/early evening. Do you think we need more time budgeted? If so, we would probably skip Bern and just head to Zurich late on our last night in Switzerland to sleep near the airport.

Just back from Zermatt and yes, give it one more day. Of course, now is the height of ski season with all the après ski hoopla, but everyone swears the summer is the best time. The lifts will all be running in July for hiking and mountain biking. Yes, it is a resort towns with lots of hotels from the grand to the budget, restaurants of all kinds from fondue with an accordion band to international cuisine to pizza parlor. So weather is a factor in that you might hit it on an off day. Two days will give you a better shot at getting that clear alpine air.
edit. Oh yes, there are still farms in Zermatt and they do take livestock (cows, sheep, goats) up on the high meadows in the summer. One, the tourists love to see them with their fancy bells, and two, they help keep the vegetation down on the ski runs, and three, they make cheese that tourists love to buy. We got a whole dissertation on how the milk from the first spring growth gives a stronger tasting (and thus pricier) cheese than later in the summer when the cows munch on the second growth.

Sorry! I said the castle was in Leytron but it's in Saillon, one town west of Leytron...sheesh.