and if ness rebooking on another airline .... the airline cannot sit back and say the next flight is 5 days time on our airline and leave it there - they have to rebook you on someone else/reroute
Actually that is NOT in the Regulation. Many network airlines will do this, but the Regulation does not require them to.
My fear is that as compensation claims become more and more ridiculous the network airlines are going to stop going beyond what the Regulation requires. Particularly those without status with them.