Is the one who gives up on marriage because he can`t afford it considered sinful?
Marriage is desirable, but one who can`t afford it isn`t considered sinful. However, he should supplicate to Allah, and seek His forgiveness.
My husband wanted to sell a piece of land that was his own, but his father insisted that he transfer the land in his (the father’s) name so that he could sell it at a higher price. Then, my husband and his father would split the price. After my father-in-law sold the land, he denied everything and refused to acknowledge my husband’s right. My father-in-law passed away a year ago, and my husband’s brothers divided the inheritance, refusing to acknowledge that this land was a trust held by their father for my husband until it was sold. Are they sinful for knowingly denying that the land belongs to my husband, and what is the ruling on praying against them?
All perfect praise be to Alalh, The Lord of The Worlds, and may His Peace and Blessings be upon our Prophet Muhammad and upon all of his family and companions.
Among the rights of the deceased upon their heirs are: preparing them for burial at death, settling their debts, returning people’s rights to them, executing their will, and then dividing their estate. What was mentioned in the question falls under the rights of others, even if they are among the heirs, and the deceased is not absolved of it unless it is returned to its rightful owners. This is because Allah, Almighty, forbids consuming others' wealth/properties unjustly. However, do not give up on seeking a solution by involving righteous and well - respected individuals who may have influence over them, in the hope that Allah guides them to goodness and correctness. As for supplicating against them, the prayer of the oppressed is not rejected, even if the oppressed person is not a Muslim. And Allah knows best.
Is permissible to buy/sell with non-Muslim?
Yes buying/selling for a Muslim with non-Muslim is permissible as regards what is lawful.
Does ill-gotten money hinder the answering of the Du`a (supplication) and the means of subsistence?
Sins hinder the answering of the Du`a, and deprive the sinner from means of subsistence; whereas, acts of obedience facilitate making a living. Allah, The Almighty, Says (What means) : "And for those who fear God, He (ever) prepares a way out. And He provides for him from (sources) he never could imagine." [At-Talaq/2-3].
