Your entrance and kitchen both are in good location as per Vastu.
Crystal ball comes under feng shui and it's regarded as a very powerful method in feng shui. It helps in creating a balance in the space in which it is used (hung/placed). The energy contained in a crystal ball is clean and pure, thus it helps in providing many benefits. Crystal ball can be used in many ways in feng shui; however, you need to know what way it would help you.
Southeast is regarded as the direction for wealth and prosperity in Feng shui. Hanging a crystal ball in this direction in the prominent areas of your home will help in getting positive energy. This will turn your negative fortunes into positive ones and will help you succeed and create more opportunities to make money.
People, who want to gain wealth and improve their financial status, should display a particular number of crystal balls in the centre of their living space. These crystal balls can be made with any crystal that is regarded good in feng shui; however you need to buy the one that is made from crystal, which is good for your situation.
You can also hang it in the Northwest corner of the building or in the Northwest room. It helps to improves relationships between the family members. It also brings in helpful people to your life. It improves money matters and brings good luck.
According to Bagua theory, different directions should be focused on for different issues of life.