Is it permissible to accept money or use items from a brother who works in designing and selling immodest women's clothing and who does not pray? And is a person held accountable for disliking him for the sake of Allah due to his sins?

Selling and designing revealing women's clothing for women who display their adornments (mutabarrijat) is haram because it is assisting in sin. If he sells it to women in general, the ruling of prohibition for the price is not definitive, as there is a possibility that some women may wear it for their husbands. Advise your brother to leave his work and maintain his prayers. Shun him if shunning him will deter him; otherwise, do not shun him. It is preferable not to accept his gifts.