Pressing Clutch a lot is definitely bad for the health of a clutch plate. I am pretty sure this statement stands true for most of the cars, I don't know the technical reasons for it, but I've heard it from a lot of people. I think its best to keep the clutch pressed for the least amount of time. However, if this can be confirmed that its not bad for the clutch plate, then its technically same to coast using the clutch. But its also a little difficult to keep pressing the clutch for a longer time instead of shifting to neutral and releasing it.
To decelerate by releasing the accelerator is pretty much same as putting it in neutral and hitting the breaks, or just hitting the breaks while still the car is in gear. Basically, you have to 'anticipate' well deceleration before time. So that instead of using the breaks, you can coast to the point where you intend to stop.