About the burnt shadows topic, I also think you still have almost black shadows, while it seems realistic to me under a vivid sunlight, I'm not fond of this part of our reality

I tried to find some light and dark balance that would please me without going too far into the black, I used your first and last attempt at trees:

Now for the eyes killing grass, I don't know, its also related to how big the screen size is (if it is a game), the smaller the screen, the less attention this grass will draw in terms of mass. How about a sneak peek at Minish Cap, approximately twice screens:
