Re: SBB 1 day travel pass without halbtax?
For at least a year, I don't know of a regular SBB/CFF day travel pass that you can get directly from SBB/CFF that doesn't require a half-fare card.
As mentioned, there are day travel passes sold at the commune / gemeinde offices that don't need a half-fare card. They are limited in number per day, though, and communes put limits on how many such passes can be bought by each resident per time period (e.g. in Lausanne, it is a maximum of 3 per month per resident). They are date fixed; you pick a date for the travel pass, and once you have signed and bought it, you can't exchange or refund it.
Also, sometimes Coop have promotions where you can buy open date day travel passes which also do not require a half-fare card.
The current SBB/CFF promotion for 2 or more people requires that at least one member of the group travelling has a half-fare card or GA.