Is it permissible for someone who distributes the proceeds of haram (unlawful) bank interest to take from it to pay off his debts and needs, or to help a relative with the expenses of ruqyah (Islamic exorcism), or to establish an Islamic forum based on the methodology of Ahlus-Sunnah, knowing that he is about to get married, his debts are few, and he intends to distribute the remainder to the needy, the poor, and orphans?

The first option is to speak with your colleague and explain your need, the needs of your relatives, and your debts. If you are too shy, there is no harm in giving to one of your needy relatives. As for yourself, we have already clarified the scholarly disagreement regarding an agent taking from Zakat (definition) if they are needy. It is not advisable to spend any of this money on establishing an Islamic forum, because the man instructed it to be distributed among the poor, the indebted, and the needy. However, you can speak with the man, and if he gives something for the establishment of the forum, then there is no harm.