Hello Roowhaukiett47
That’s quite a busy itinerary, but doable.
The Swiss Travel Pass is the equivalent of the GA travel card; the latter is the resident pass, while the Swiss Travel Pass is for visitors. You are welcome to choose GA travel card as reduction type.
But, there is really no need to purchase seat reservations for 1st class, and is often not even possible. Seat reservations are only possible for trains of category InterCity (IC), or international trains. IR and RE trains do not offer seat reservations at all.
You can find out more by reading our guide:
https://community.sbb.ch/blog/23887-demystifying-seat-reservations-on-swiss-trains-a-comprehensive-guide
I suggest you to download the SBB Mobile App. If you need additional tickets, you can easily purchase them through the app. Under tab Profile you can add co-travelers. When purchasing a ticket, tap on the pen icon displayed above the ticket selection in order to modify reductions and to select the passengers for whom you want to purchase a ticket. The app also includes all schedules of all public transport services in Switzerland.
Kind regards,
Roland