mrbradshaw
Nobody says a tourist can’t get a yearly Half Fare Travelcard (which is NOT available “monthly” as you mentioned in your initial post!) or other yearly pass, it’s just very unusual. Such yearly subscription-type products loaded onto the SwissPass are just intended for residents, using public transport services for several years.
The vast majority of foreign tourists would usually prefer the very similar, but roughly ⅓ cheaper “Swiss Half Fare Card”, which is a “quick & dirty” 1-month version of the HF travelcard, coming as electronic document only. (Read: no hassle or paperwork regarding ID check, providing a suitable foto and a postal address for sending the physical SwissPass card after 10 days + the renewal invoice after 10 months)
Regarding your 2nd question, see details => here (related to the 1-year HF travelcard on SwissPass!)
Maybe better use the postal address of your first accomodation in CH, not sure whether a “poste restante” consignment at the airport Post Office branch would be accepted. When buying online, you’re supposed to get a temporary PDF document valid until the physical card is produced and delivered anyway.
3rd question - basically yes, see details => here (NOT applicable for typical tourists! 😁)