Ingame - low quality

Maybe it is a newbie question, but I have got a strange problem with my shadows. I use a terrain with objects on it. In editor view the shadows look fantastic. I set them to "very high resolution" and the directional light to "important". When I run the game the shadows look like they would in editor look like if I enable "two cascades" or "no cascades" in the quality options. Is there any option I am missing? I set the quality mode to "fantastic".

I have got also a water plane "crossing" my terrain object. In editor mode it looks fine, but in game mode the parts where the plane and the tarrain touch are flickering terribly. I have already set the clipping range of the camera to the highest possible level, before everything becomes laggy.

Any idea what I do wrong? I use Unity Indie, latest Version. Thanks for any help.