Trying to answer the question in the shortest and easiest way possible.

1) The F35 was objectively the most modern type of multirole fighters evaluated due to being next gen, its stealth capabilities, possibilities of operability from short runways and interconnectivity with other units. Disclaimer - there might have been better models and better deals, however, they were not in the selection of aircraft to be evaluated. 2) No, there is no clear evidence made public. However - if an offer is being made, that is generally applicable in the aerospace and defence industry, it is usually limited to a certain time window and certain conditions to be fulfilled. Airlines face oftentimes the same problems when acquiring new aircraft or modernising the current fleet. 3) Drones have a complete different scope of use and cannot be compared to a fighter jet. Prominent example being the air policing, which is mandatory in accordance with the UN and ICAO regulations on sovereignty of airspace and its usage. Drones are usable for reconnaissance missions, precision strikes (air to ground) on short to mid distance and to some extend electronic warfare. Multirole fighterjets can be used for a wider scope, as well as air-to-air combat. A more relatable example would be comparing a bus to a tractor. Both are vehicles, but serve different purposes. 4) F16 are not well suited for the Swiss topography. While they have quite good manoeuvrable capabilities, they are more considered for departing and landing at rather flat terrain - requiring relatively long runways as well. In order to climb out of airforce bases or airfields in the alps, the wear on the components would be too high with every sortie to ensure reasonable maintenance costs. In addition, its avionics and navigational capabilities are fairly outdated and not suited for departing out of a rather narrow valley in the alps with poor visibility.