1. now only miles&more (LX, LH, OS, LOT) - formerly also Flying Dutchman (KLM) and Mileage Plus (UA)

2. as a SEN (miles&more) the partner awards that cost only 150% of the miles (2nd: fast check-in at 1st class counter, even when flying eco)

3. YES, LH SEN (qualification criteria are: must be over 60, must have been unniterrupted SEN for 10 years and still be SEN when applying, must have over 1 Mio lifetime flight-mileage credits, must apply - not granted automatically )

4. YES, Mileage Plus (UA): I was 1K with them, but gave up using them when they cancelled flying from ZRH (to IAD); when they resumed ZRH-IAD 3 years later I asked and got 1K again.