It is not permissible to sell tobacco because of its great harms. The person who sells it is a disobedient person. A person is not required to perform his Wudu' again because of smoking
tobacco. But he is recommended to remove this bad smell in his mouth due to smoking with anything that can remove it. One should repent to Allah from doing so.
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.