Who has actually operated the fligt ETZ-LYS?
A5?
Also since the flight was both coded and operated by A5 does it qualify for the usual 350euros compensation for delayed/canceled flight, or are there specific T&C for A5?
It does not matter what A5 states in their T&C.
The rights of EC261/2004 cannot be limited by T&C.
I would claim EUR 250 in EC261/2004 compensation at A5.
In addition I would also claim the train ticket and hotel price.