Is the testimony of one who was martyred in the cause of Allah accepted if he owed financial and moral dues to people that he was unable to fulfill? And will Allah take from his good deeds to pay them to those who are entitled to them? And are financial and moral dues equal in terms of taking from good deeds?

The consequences of one's actions (the rights of other people, whether material or moral) are not forgiven for the martyr. In the Hadith (definition), "Everything is forgiven for the martyr except debt," and by "debt" is meant the rights of human beings concerning their wealth, blood, and honor. However, if the martyr has good deeds, these may benefit him in balancing out what is due from him, and his degree of martyrdom will remain pure. But if he has no good deeds, then he is subject to Allah's will.