You could use the Mental Ray Dielectric materials, then of course you would have to render in mental ray, a better option would be to just play with the transparancy of a blinn material (or whatever material you choose)

Softbodies sounds good for the kite material, but if its that far way in the shot would you really notice the movement of the material??

If you can a hair fmight tbe the best option as softbodies and springs can stretch an be quite unpredictable. To ainmate the tail just use fields or a wave deformer and fields (like turbulance)

Just some ideas