Half Fare Ticket

Hopefully someone will respond with current knowledge but I remember being told last year when debating on which SBB card to purchase that the prices shown are the half prices.

You do not need the Half Fare Card in your possession to buy tickets at half fare, you only need it in your possession when they check your ticket on the train. That is the way it works in Switzerland. They trust you to know the rules. So just buy tickets at half fare and make sure you have the card on you when you board the train.

BTW, do you know what a Saver Day Pass is? Today, you can buy a 2nd class Saver Day Pass for June 25 for 49 CHF per person, about $60 US, or $120 for 2 people, saving you a lot of money. It is nonrefundable and only good on that day, so be sure of your plans. Prices go up as time goes by, You can also buy it without the Half Fare Card for 61 CHF, or $74 pp.
https://www.sbb.ch/en/tickets-offers/tickets/day-passes/saver-day-pass.html

But the general rule is, if your total tickets pp is more than 240 CHF, then the Half Fare Card will definitely save you money. It is a tad confusing quoting prices in dollars. In Switzerland, everything is in Swiss Francs.

In general you should not pre-purchase tickets unless it’s a Saver Day Pass or a reservation for something that will sell out. The routes you listed will not sell out, so purchasing regular tickets now is not necessary.

Get the HFC directly from SBB the day before you travel and just purchase tickets right before you get on the train via the SBB app or the ticket machines at the station.

Also good to know:

The Half Fare Card will also give you half price travel up mountains. You will see it listed as the ‘Swiss Half Fare Card’ (this is the one month tourist one), as seen here on the the Gornergrat Railway website under ‘discounts’:

https://www.gornergrat.ch/en/pages/prices-gornergrat-bahn

Using the SBB app is extremely helpful. You can add every person that is traveling with you, enter that they have the HFC and all tickets will be at the proper discount. While traveling you will be informed of any delays, platform changes, etc. and be prepared for that before you even arrive at the station.

Put it on your phone now and just play around with it until your trip so that you get used to how to use it. You can even see the direction your train will travel - helpful if you like to face forward, and also which cars are predicted to be less busy, etc.

I like to buy my tickets on the app and do so before traveling to the station.

After purchasing the ticket do they any changes to time, just in case?

Train times are fixed and only changed if something unforeseen happens causing a delay, but in general Swiss trains leave exactly as scheduled.

For the routes you mention, your ticket will be valid for the entire day, not just the time that you plan on traveling. You can easily take a later train using that same ticket if you so desire.

We just returned from 7 days in Switzerland. We did get a 6 day SBB pass. All we needed with the QRcode saved on our phone or a paper pass and we could get on any second class cabin, marked with the Number 2 on the outside. I did purchase the passes before we left the states. All of the train stations have very helpful agents willing to talk you through all of it. Most stations actually have the location of first and second class shown by the platform it is leaving from on the lit up display above the platform.. We just had to decide what time and where we were going.
I recommend also checking on line for how crowded the train can be if you have luggage. We ended up a few times with our luggage on our laps because it was crowded and the luggage racks were full. The SBB app is very helpful.
The SBB pass does cover boat trips, very nice, museum discounts, and many hotels provide free bus transportation also very convenient.
We did reserve one first class ticket for a panoramic trip, but as it turned out it wasn't really necessary other than paying extra for a reserved seat.

For some trains the station displays now even show how full each car is, so you can position yourself so that you end up in one of the quieter cars. Although I expect that this will lead to loadings becoming more even, which is actually not a bad thing.