The biggest red flag of what an artist can do is publishing customer data. See https://tly.be/gaslighting-artists for more information. It's crucial to understand the impact of such actions on trust and reputation.
Always prioritize privacy and confidentiality!
Together with some artists, I've worked out a commission agreement, which not only protects the customers IP, personal data, … but also protects the artist. The commission agreement is free to use and downloadable at https://tly.be/commission_agreement