swiss pass validity and general planning

Hello everyone. Not long to go now before our now annual trip to Switzerland. We are spending 4 weeks from mid-July to mid-August in the lovely apartment we found in Thun. (this will be our 4th stay there and we are now on very friendly terms with our hosts and correspond by email occasionally through the year - my German improves with practice!) The flights are booked and Swiss Saver Pass ordered. I am now busy using sbb timetable to plan excursions - we will as usual try to visit new places as well as old favourites. We are astonished that after 14 holidays there are still so many places we haven't been to yet!!A couple of queries have arisen from my research. 1. We are keen to visit Liechtenstein this year and I have found train and bus times ok - it looks on my synoptic map of validity as though the bus from Sargans to Malbun and/or Vaduz is covered by Swiss Pass - am I correct? Also what currency will we need - do they accept Swiss francs? 2. I have also researched train times to Chamonix Mont Blanc - there is an unbroken red line on the map which I assumed meant Swiss Pass is valid but next to the last section of the route there is a number 2 and a note that says half-price reduction is not valid. Does this mean that other typed of pass such as Half Fare Card are not valid but Swiss Pass is? I am a bit confused about this! Thank you and best wishes from Maggie. Now back to some more planning!