The house faces the hill in the south, and the valley is gentle in Feng Shui.

That means your home is behind the recess of the hill, or behind the gentle sides of the hill? The former is not good. If you want to see it from this side of the mountain, wouldn't it look like your house is right on the target of a gun if it happens to be in that recess? So the latter is better, but the location is lower. The wind from the other side of the mountain will not rush directly to your home, but will rush upward and then blow downward.