I agree with the above I'm afraid.
Search 'scenic resistor pack' in the forum search tool for the heater fan problem
rear windows could well be the regulators, again well covered on the form, although iirc you can isolate the rear windows.
I would think that the water is a leak and the dealer is trying to pull the wool over your eyes
The electronic parking brakes have caused problems, and again there are threads on the forum.
Renault clutches are a little odd in that the bite point has been different on every Renault I've driven, and I've driven quite a lot. It's probably fine
The service light is probably registering a fault, and that could be any number of things
and you won't get much change out of £150 for a new key card.
If I were you, I'd continue looking