1. It was the beginning of civilization and brought massive change from going from the nomadic lifestyle to the farming, village one instead. They adopted a sedentary way of life, by doing this they created early cities which housed their growing population. From living a sedentary lifestyle their people grew skills of farming, manufacturing and harvesting.
2. They did pottery such as terracotta sculptures which was a major art form for them. Furthermore, they had mobiliary art including sculpted statuettes and personal adornments. In a like manner, they constructed reigious temples, shrines and tombs which influenced the development of megalithic art.
3. The main theme of imagery in Neolithic art is female and fertility, bascially goddesses.
4. Characteristics that I know of are fertility symbols called Venus figurines. That's all I know with this question.