May 7, 2016 - 12:08 PM
1. The Swiss Travel Pass validity is measured in dates, not in 24 hour periods. So it doesn't matter at what time you first your use pass. That day will just count as your first free travel day. So if you start using your pass on Monday, it will be valid on Monday, Tuesday and Wednesday (up to 05h00 in the early morning of Thursday). It's explained here too.
2./3. Your trips in/from Geneva and Zurich won't be covered by a 3 day Swiss Travel Pass, so these may require additional tickets. You can use local passes as explained here and here though. Apart from that, you'll have to pay for the rides Alpnachstad-Pilatus and Pilatus-Kriens indeed. The boat part of the Golden Round trip will be covered by your Swiss Travel Pass. Seat reservations aren't required for your plans.
4. Whether a Swiss Half Fare Card is more economical should be calculated. Apart from prices, you'll also have to take convenience into account. If you don't mind buying additional discounted tickets for each trip, a Swiss Half Fare Card may work. If you prefer the convenience of free ticketless traveling, and the flexibility to change or extend any of your plans, the 3 day Swiss Travel Pass is better.
5. It's easier to buy in advance. Purchase options are listed here and here. If you pick www.swissrailways.com/ en, you'll receive online print at home passes without any additional shipping or handling fees. You won't have to spend time buying your passes at the Geneva railway station this way.