What is the ruling o associations (Whereas a person who have money buys a commodity for a person and and gets a profit on it)?
It is permissible for a person to buy a commodity for someone's else and have a profit/loss on it
I work in an accounting and auditing office, and among the clients of the office are restaurants, hotels, and supermarkets that sell alcohol. Our work is limited to collecting invoices, whether purchases, sales, or expenses, and recording them in daily books. We also review income and sales taxes on behalf of these clients.
You are more knowledgeable about the nature of your work. If you see it as assisting in wrongdoing, then it is forbidden, as Allah The Exalted Says (What means): "And cooperate in righteousness and piety, but do not cooperate in sin and aggression" [Al-Ma’idah/2]. However, if your work is merely documenting the reality, then I hope there is no sin upon you. The the pious predecessors (Salaf) used to take the tithe from the traders of the People of the Book, even if it included alcohol, after knowing the value of their goods. And Allah The Almighty Knows Best.
A pious man proposed to me and my father was hesitant in this regard because he is black, am I sinful if I accepted his proposal?
If the suitor is pious, color isn`t a drawback. However, try talking to your father kindly, so that he approves of your marriage with contentment, and that is better for you.
Is it permissible for a woman who is in her confinement to fast upon seeing blood signs that are neither black, nor red ?
Brownish, reddish, and yellowish discharges are all considered confinement until there is no colored discharge which marks the end of confinement. Moreover, the aforesaid woman is prohibited from fasting until she attains ritual purity. And Allah Knows Best.