Hi zaviour
Yes, you can buy Save Day Passes as a tourist, that’s no problem.
Forget the GA, you don’t need it. A GA costs CHF 3,860.00 per year at the normal price and gives our customers free travel throughout the country using most means of transport.
What you could consider, however, is a Swiss Half-Fare Card, which entitles you to buy tickets (and also saver day tickets) at a cheaper price for an entire month as a tourist. You can find more information here: Swiss Half-Fare Card
I wish you a great day.