When the sun is getting nearer why is the shadow growing longer?
You mean, when the sun appears nearer to the horizon? Because then the sun is farther away.
Or do you mean, when the sun is nearer to the camera (and therefore higher in the sky)? Then the shadows are shorter. At what time position do they appear longer to you?
Also the mountain's shadow is supposed not that sharp.
Yes, that is normal with a nearly cloudless sky, especially when it is cold and the atmosphere is clear. And also keep in mind, that the camera is at some distance to the shadows. It is over 500 m above sea level. Therefore, the mountains in the background casting the shadows are a few kilometers away. Also the shadows area at some distance. Therefore, you won't see much penumbra.
Also the sea waving is too slow for the sun's movement. That's not a real timelapse.
The water is very still in the bay. It could be almost standing waves. But you could see the ice growing and melting on the water.